Substituted nucleosides, nucleotides and analogs thereof

ABSTRACT

Disclosed herein are nucleosides, nucleotides and analogs thereof, pharmaceutical compositions that include one or more of nucleosides, nucleotides and analogs thereof, and methods of synthesizing the same. Also disclosed herein are methods of ameliorating and/or treating a disease and/or a condition, including an infection from a paramyxovirus and/or an orthomyxovirus, with a nucleoside, a nucleotide and an analog thereof.

This application claims the benefit of U.S. Provisional Application Nos.61/579,560, filed Dec. 22, 2011; and 61/613,836, filed Mar. 21, 2012;which are incorporated herein by reference in their entireties;including any drawings.

BACKGROUND

1. Field

The present application relates to the fields of chemistry, biochemistryand medicine. More particularly, disclosed herein are nucleoside,nucleotides and analogs thereof, pharmaceutical compositions thatinclude one or more nucleosides, nucleotides and analogs thereof, andmethods of synthesizing the same. Also disclosed herein are methods ofameliorating and/or treating a paramyxovirus and/or an orthomyxovirusviral infection with one or more nucleosides, nucleotides and analogsthereof.

2. Description

Respiratory viral infections, including upper and lower respiratorytract viral infections, infects and is the leading cause of death ofmillions of people each year. Upper respiratory tract viral infectionsinvolve the nose, sinuses, pharynx and/or larynx. Lower respiratorytract viral infections involve the respiratory system below the vocalcords, including the trachea, primary bronchi and lungs.

Nucleoside analogs are a class of compounds that have been shown toexert antiviral activity both in vitro and in vivo, and thus, have beenthe subject of widespread research for the treatment of viralinfections. Nucleoside analogs are usually therapeutically inactivecompounds that are converted by host or viral enzymes to theirrespective active anti-metabolites, which, in turn, may inhibitpolymerases involved in viral or cell proliferation. The activationoccurs by a variety of mechanisms, such as the addition of one or morephosphate groups and, or in combination with, other metabolic processes.

SUMMARY

Some embodiments disclosed herein relate to a compound of Formula (I),Formula (II) and/or Formula (III), or a pharmaceutically acceptable saltof the foregoing.

Some embodiments disclosed herein relate to methods of amelioratingand/or treating a paramyxovirus viral infection that can includeadministering to a subject suffering from the paramyxovirus viralinfection an effective amount of one or more compounds of Formula (I),Formula (II) and/or Formula (III), or a pharmaceutically acceptable saltof the foregoing, or a pharmaceutical composition that includes one ormore compounds of Formula (I), Formula (II) and/or Formula (III), or apharmaceutically acceptable salt of the foregoing. Other embodimentsdescribed herein relate to using one or more compounds of Formula (I),Formula (II) and/or Formula (III), or a pharmaceutically acceptable saltof the foregoing, in the manufacture of a medicament for amelioratingand/or treating a paramyxovirus viral infection. Still other embodimentsdescribed herein relate to compounds of Formula (I), Formula (II) and/orFormula (III), or a pharmaceutically acceptable salt of the foregoing,that can be used for ameliorating and/or treating a paramyxovirus viralinfection. Yet still other embodiments disclosed herein relate tomethods of ameliorating and/or treating a paramyxovirus viral infectionthat can include contacting a cell infected with the paramyxovirus withan effective amount of one or more compounds of Formula (I), Formula(II) and/or Formula (III), or a pharmaceutically acceptable salt of theforegoing, or a pharmaceutical composition that includes one or morecompounds of Formula (I), Formula (II) and/or Formula (III), or apharmaceutically acceptable salt of the foregoing. Some embodimentsdisclosed herein relate to methods of inhibiting the replication of aparamyxovirus that can include contacting a cell infection with theparamyxovirus with an effective amount of one or more compounds ofFormula (I), Formula (II) and/or Formula (III), or a pharmaceuticallyacceptable salt of the foregoing, or a pharmaceutical composition thatincludes one or more compounds of Formula (I), Formula (II) and/orFormula (III), or a pharmaceutically acceptable salt of the foregoing.For example, the paramyxovirus viral infection can be caused by ahenipavirus, a morbillivirus, a respirovirus, a rubulavirus, apneumovirus (including a respiratory syncytial viral infection), ametapneumovirus, hendravirus, nipahvirus, measles, sendai virus, mumps,a human parainfluenza virus (HPIV-1, HPIV-2, HPIV-3 and HPIV-4) and/or ametapneumovirus.

Some embodiments disclosed herein relate to methods of amelioratingand/or treating an orthomyxovirus viral infection that can includeadministering to a subject suffering from the orthomyxovirus viralinfection an effective amount of one or more compounds of Formula (I),Formula (II) and/or Formula (III), or a pharmaceutically acceptable saltof the foregoing, or a pharmaceutical composition that includes one ormore compounds of Formula (I), Formula (II) and/or Formula (III), or apharmaceutically acceptable salt of the foregoing. Other embodimentsdescribed herein relate to using one or more compounds of Formula (I),Formula (II) and/or Formula (III), or a pharmaceutically acceptable saltof the foregoing, in the manufacture of a medicament for amelioratingand/or treating an orthomyxovirus viral infection. Still otherembodiments described herein relate to compounds of Formula (I), Formula(II) and/or Formula (III), or a pharmaceutically acceptable salt of theforegoing, that can be used for ameliorating and/or treating anorthomyxovirus viral infection. Yet still other embodiments disclosedherein relate to methods of ameliorating and/or treating anorthomyxovirus viral infection that can include contacting a cellinfected with the orthomyxovirus with an effective amount of one or morecompounds of Formula (I), Formula (II) and/or Formula (III), or apharmaceutically acceptable salt of the foregoing, or a pharmaceuticalcomposition that includes one or more compounds of Formula (I), Formula(II) and/or Formula (III), or a pharmaceutically acceptable salt of theforegoing. Some embodiments disclosed herein relate to methods ofinhibiting the replication of an orthomyxovirus that can includecontacting a cell infection with the orthomyxovirus with an effectiveamount of one or more compounds of Formula (I), Formula (II) and/orFormula (III), or a pharmaceutically acceptable salt of the foregoing,or a pharmaceutical composition that includes one or more compounds ofFormula (I), Formula (II) and/or Formula (III), or a pharmaceuticallyacceptable salt of the foregoing. For example, the orthomyxovirus viralinfection can be an influenza viral infection (such as influenza A, Band/or C).

Some embodiments disclosed herein relate to methods of amelioratingand/or treating a paramyxovirus viral infection and/or an orthomyxovirusviral infection that can include administering to a subject sufferingfrom the viral infection an effective amount of a compound describedherein or a pharmaceutically acceptable salt thereof (for example, oneor more compounds of Formulae (I), (II) and/or (III), or apharmaceutically acceptable salt of the foregoing), or a pharmaceuticalcomposition that includes one or more compounds described herein, incombination with one or more agents described herein. Some embodimentsdisclosed herein relate to methods of ameliorating and/or treating aparamyxovirus viral infection and/or an orthomyxovirus viral infectionthat can include contacting a cell infected with the virus with aneffective amount of a compound described herein or a pharmaceuticallyacceptable salt thereof (for example, one or more compounds of Formulae(I), (II) and/or (III), or a pharmaceutically acceptable salt of theforegoing), or a pharmaceutical composition that includes one or morecompounds described herein, in combination with one or more agentsdescribed herein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows example RSV agents.

DETAILED DESCRIPTION

Paramyxoviridae family is a family of single stranded RNA viruses.Several genera of the paramyxoviridae family include henipavirus,morbillivirus, respirovirus, rubulavirus, pneumovirus andmetapneumovirus. These viruses can be transmitted person to person viadirect or close contact with contaminated respiratory droplets orfomites. Species of henipavirus include hendravirus and nipahvirus. Aspecies of morbillivirus is measles. Species of respirovirus includesendai virus and human parainfluenza viruses 1 and 3; and species ofrubulavirus include mumps virus and human parainfluenza viruses 2 and 4.A species of metapneumovirus is human metapneumovirus.

Human Respiratory Syncytial Virus (RSV), a species of pneumovirus, cancause respiratory infections, and can be associated with bronchiolitisand pneumonia. Symptoms of an RSV infection include coughing, sneezing,runny nose, fever, decrease in appetite, and wheezing. RSV is the mostcommon cause of bronchiolitis and pneumonia in children under one yearof age in the world, and can be the cause of tracheobronchitis in olderchildren and adults. In the United States, between 75,000 and 125,000infants are hospitalized each year with RSV. Among adults older than 65years of age, an estimated 14,000 deaths and 177,000 hospitalizationshave been attributed to RSV.

Treatment options for people infected with RSV are currently limited.Antibiotics, usually prescribed to treat bacterial infections, andover-the-counter medication are not effective in treating RSV and mayhelp only to relieve some of the symptoms. In severe cases, a nebulizedbronchodilator, such as albuterol, may be prescribed to relieve some ofthe symptoms, such as wheezing. RespiGram® (RSV-IGIV, MedImmune,approved for high risk children younger than 24 months of age), Synagis®(palivizumab, MedImmune, approved for high risk children younger than 24months of age), and Virzole® (ribavirin by aerosol, ICN pharmaceuticals)have been approved for treatment of RSV.

Symptoms of the measles include fever, cough, runny nose, red eyes and ageneralized rash. Some individuals with measles can develop pneumonia,ear infections and bronchitis. Mumps leads to swelling of the salivaryglands. Symptoms of mumps include fever, loss of appetite and fatigue.Individuals are often immunized against measles and mumps via athree-part MMR vaccine (measles, mumps, and rubella). Humanparainfluenza virus includes four serotypes types, and can cause upperand lower respiratory tract infections. Human parainfluenza virus 1(HPIV-1) can be associated with croup; human parainfluenza virus 3(HPIV-3) can be associated with bronchiolitis and pneumonia. Accordingto the Centers of Disease Control and Prevention (CDC), there are novaccines against human parainfluenza virus.

Influenza is a single stranded RNA virus and a member of theOrthomyxoviridae family. There are currently three species of influenza;influenza A, influenza B and influenza C. Influenza A has been furtherclassified based on the viral surface proteins into hemagglutinin (H orHA) and neuramididase (N). There are approximately 16H antigens (H1 toH16) and 9 N antigens (N1 to N9). Influenza A includes several subtype,including H1N1, H1N2, H2N2, H3N1, H3N2, H3N8, H5N1, H5N2, H5N3, H5N8,H5N9, H7N1, H7N2, H7N3, H7N4, H7N7, H9N2, H10N7. As with RSV, influenzaviruses can be transmitted from person to person via direct contact withinfected secretions and/or contaminated surfaces or objections.Complications from an influenza viral infection include pneumonia,bronchitis, dehydration, and sinus and ear infections. Medicationscurrently approved by the FDA against an influenza infection includeamantadine, rimantadine, Relenza® (zanamivir, GlaxoSmithKline) andTamiflu® (oseltamivir, Genentech).

DEFINITIONS

Unless defined otherwise, all technical and scientific terms used hereinhave the same meaning as is commonly understood by one of ordinary skillin the art. All patents, applications, published applications and otherpublications referenced herein are incorporated by reference in theirentirety unless stated otherwise. In the event that there are aplurality of definitions for a term herein, those in this sectionprevail unless stated otherwise.

As used herein, any “R” group(s) such as, without limitation, R^(1A),R^(2A), R^(3A), R^(4A), R^(5A), R^(6A), R^(7A), R^(8A), R^(9A), R^(10A),R^(11A), R^(12A), R^(13A), R^(14A), R^(15A), R^(16A), R^(17A), R^(18A),R^(19A), R^(20A), R^(21A), R^(22A), R^(23A), R^(24A), R^(25A), R^(26A),R^(27A), R^(28A), R^(29A), R^(30A), R^(31A), R^(32A), R^(33A), R^(34A),R^(35A), R^(36A), R^(37A), R^(38A), R^(1B), R^(2B), R^(3B), R^(4B),R^(5B), R^(6B), R^(7B), R^(8B), R^(9B), R^(10B), R^(11B), R^(12B),R^(13B), R^(14B), R^(1C), R^(2C), R^(3C), R^(4C), R^(5C), R^(6C),R^(7C), R^(8C), R^(9C), R^(10C), R^(11C), R^(12C), R^(13C), R^(14C),R^(15C), R^(16C), R^(17C), R^(18C), R^(19C), R^(20C), R^(21C), R^(22C)and R^(23C) represent substituents that can be attached to the indicatedatom. An R group may be substituted or unsubstituted. If two “R” groupsare described as being “taken together” the R groups and the atoms theyare attached to can form a cycloalkyl, cycloalkenyl, cycloalkynyl, aryl,heteroaryl or heterocycle. For example, without limitation, if R^(a) andR^(b) of an NR^(a)R^(b) group are indicated to be “taken together,” itmeans that they are covalently bonded to one another to form a ring:

In addition, if two “R” groups are described as being “taken together”with the atom(s) to which they are attached to form a ring as analternative, the R groups are not limited to the variables orsubstituents defined previously.

Whenever a group is described as being “optionally substituted” thatgroup may be unsubstituted or substituted with one or more of theindicated substituents. Likewise, when a group is described as being“unsubstituted or substituted” if substituted, the substituent(s) may beselected from one or more of the indicated substituents. If nosubstituents are indicated, it is meant that the indicated “optionallysubstituted” or “substituted” group may be substituted with one or moregroup(s) individually and independently selected from alkyl, alkenyl,alkynyl, cycloalkyl, cycloalkenyl, cycloalkynyl, aryl, heteroaryl,heteroalicyclyl, aralkyl, heteroaralkyl, (heteroalicyclyl)alkyl,hydroxy, protected hydroxyl, alkoxy, aryloxy, acyl, mercapto, alkylthio,arylthio, cyano, halogen, thiocarbonyl, O-carbamyl, N-carbamyl,O-thiocarbamyl, N-thiocarbamyl, C-amido, N-amido, S-sulfonamido,N-sulfonamido, C-carboxy, protected C-carboxy, O-carboxy, isocyanato,thiocyanato, isothiocyanato, nitro, silyl, sulfenyl, sulfinyl, sulfonyl,haloalkyl, haloalkoxy, trihalomethanesulfonyl,trihalomethanesulfonamido, an amino, a mono-substituted amino group anda di-substituted amino group, and protected derivatives thereof.

As used herein, “C_(a) to C_(b)” in which “a” and “b” are integers referto the number of carbon atoms in an alkyl, alkenyl or alkynyl group, orthe number of carbon atoms in the ring of a cycloalkyl, cycloalkenyl,cycloalkynyl, aryl, heteroaryl or heteroalicyclyl group. That is, thealkyl, alkenyl, alkynyl, ring of the cycloalkyl, ring of thecycloalkenyl, ring of the cycloalkynyl, ring of the aryl, ring of theheteroaryl or ring of the heteroalicyclyl can contain from “a” to “b”,inclusive, carbon atoms. Thus, for example, a “C₁ to C₄ alkyl” grouprefers to all alkyl groups having from 1 to 4 carbons, that is, CH₃—,CH₃CH₂—, CH₃CH₂CH₂—, (CH₃)₂CH—, CH₃CH₂CH₂CH₂—, CH₃CH₂CH(CH₃)— and(CH₃)₃C—. If no “a” and “b” are designated with regard to an alkyl,alkenyl, alkynyl, cycloalkyl cycloalkenyl, cycloalkynyl, aryl,heteroaryl or heteroalicyclyl group, the broadest range described inthese definitions is to be assumed.

As used herein, “alkyl” refers to a straight or branched hydrocarbonchain that comprises a fully saturated (no double or triple bonds)hydrocarbon group. The alkyl group may have 1 to 20 carbon atoms(whenever it appears herein, a numerical range such as “1 to 20” refersto each integer in the given range; e.g., “1 to 20 carbon atoms” meansthat the alkyl group may consist of 1 carbon atom, 2 carbon atoms, 3carbon atoms, etc., up to and including 20 carbon atoms, although thepresent definition also covers the occurrence of the term “alkyl” whereno numerical range is designated). The alkyl group may also be a mediumsize alkyl having 1 to 10 carbon atoms. The alkyl group could also be alower alkyl having 1 to 6 carbon atoms. The alkyl group of the compoundsmay be designated as “C₁-C₄ alkyl” or similar designations. By way ofexample only, “C₁-C₄ alkyl” indicates that there are one to four carbonatoms in the alkyl chain, i.e., the alkyl chain is selected from methyl,ethyl, propyl, iso-propyl, n-butyl, iso-butyl, sec-butyl, and t-butyl.Typical alkyl groups include, but are in no way limited to, methyl,ethyl, propyl, isopropyl, butyl, isobutyl, tertiary butyl, pentyl andhexyl. The alkyl group may be substituted or unsubstituted.

As used herein, “alkenyl” refers to an alkyl group that contains in thestraight or branched hydrocarbon chain one or more double bonds. Analkenyl group may be unsubstituted or substituted.

As used herein, “alkynyl” refers to an alkyl group that contains in thestraight or branched hydrocarbon chain one or more triple bonds. Analkynyl group may be unsubstituted or substituted.

As used herein, “cycloalkyl” refers to a completely saturated (no doubleor triple bonds) mono- or multi-cyclic hydrocarbon ring system. Whencomposed of two or more rings, the rings may be joined together in afused fashion. Cycloalkyl groups can contain 3 to 10 atoms in thering(s) or 3 to 8 atoms in the ring(s). A cycloalkyl group may beunsubstituted or substituted. Typical cycloalkyl groups include, but arein no way limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl,cycloheptyl and cyclooctyl.

As used herein, “cycloalkenyl” refers to a mono- or multi-cyclichydrocarbon ring system that contains one or more double bonds in atleast one ring; although, if there is more than one, the double bondscannot form a fully delocalized pi-electron system throughout all therings (otherwise the group would be “aryl,” as defined herein). Whencomposed of two or more rings, the rings may be connected together in afused fashion. A cycloalkenyl group may be unsubstituted or substituted.

As used herein, “cycloalkynyl” refers to a mono- or multi-cyclichydrocarbon ring system that contains one or more triple bonds in atleast one ring. If there is more than one triple bond, the triple bondscannot form a fully delocalized pi-electron system throughout all therings. When composed of two or more rings, the rings may be joinedtogether in a fused fashion. A cycloalkynyl group may be unsubstitutedor substituted.

As used herein, “aryl” refers to a carbocyclic (all carbon) monocyclicor multicyclic aromatic ring system (including fused ring systems wheretwo carbocyclic rings share a chemical bond) that has a fullydelocalized pi-electron system throughout all the rings. The number ofcarbon atoms in an aryl group can vary. For example, the aryl group canbe a C₆-C₁₄ aryl group, a C₆-C₁₀ aryl group, or a C₆ aryl group.Examples of aryl groups include, but are not limited to, benzene,naphthalene and azulene. An aryl group may be substituted orunsubstituted.

As used herein, “heteroaryl” refers to a monocyclic or multicyclicaromatic ring system (a ring system with fully delocalized pi-electronsystem) that contain(s) one or more heteroatoms, that is, an elementother than carbon, including but not limited to, nitrogen, oxygen andsulfur. The number of atoms in the ring(s) of a heteroaryl group canvary. For example, the heteroaryl group can contain 4 to 14 atoms in thering(s), 5 to 10 atoms in the ring(s) or 5 to 6 atoms in the ring(s).Furthermore, the term “heteroaryl” includes fused ring systems where tworings, such as at least one aryl ring and at least one heteroaryl ring,or at least two heteroaryl rings, share at least one chemical bond.Examples of heteroaryl rings include, but are not limited to, furan,furazan, thiophene, benzothiophene, phthalazine, pyrrole, oxazole,benzoxazole, 1,2,3-oxadiazole, 1,2,4-oxadiazole, thiazole,1,2,3-thiadiazole, 1,2,4-thiadiazole, benzothiazole, imidazole,benzimidazole, indole, indazole, pyrazole, benzopyrazole, isoxazole,benzoisoxazole, isothiazole, triazole, benzotriazole, thiadiazole,tetrazole, pyridine, pyridazine, pyrimidine, pyrazine, purine,pteridine, quinoline, isoquinoline, quinazoline, quinoxaline, cinnoline,and triazine. A heteroaryl group may be substituted or unsubstituted.

As used herein, “heterocyclyl” or “heteroalicyclyl” refers to three-,four-, five-, six-, seven-, eight-, nine-, ten-, up to 18-memberedmonocyclic, bicyclic, and tricyclic ring system wherein carbon atomstogether with from 1 to 5 heteroatoms constitute said ring system. Aheterocycle may optionally contain one or more unsaturated bondssituated in such a way, however, that a fully delocalized pi-electronsystem does not occur throughout all the rings. The heteroatom(s) is anelement other than carbon including, but not limited to, oxygen, sulfur,and nitrogen. A heterocycle may further contain one or more carbonyl orthiocarbonyl functionalities, so as to make the definition includeoxo-systems and thio-systems such as lactams, lactones, cyclic imides,cyclic thioimides and cyclic carbamates. When composed of two or morerings, the rings may be joined together in a fused fashion.Additionally, any nitrogens in a heteroalicyclic may be quaternized.Heterocyclyl or heteroalicyclic groups may be unsubstituted orsubstituted. Examples of such “heterocyclyl” or “heteroalicyclyl” groupsinclude but are not limited to, 1,3-dioxin, 1,3-dioxane, 1,4-dioxane,1,2-dioxolane, 1,3-dioxolane, 1,4-dioxolane, 1,3-oxathiane,1,4-oxathiin, 1,3-oxathiolane, 1,3-dithiole, 1,3-dithiolane,1,4-oxathiane, tetrahydro-1,4-thiazine, 2H-1,2-oxazine, maleimide,succinimide, barbituric acid, thiobarbituric acid, dioxopiperazine,hydantoin, dihydrouracil, trioxane, hexahydro-1,3,5-triazine,imidazoline, imidazolidine, isoxazoline, isoxazolidine, oxazoline,oxazolidine, oxazolidinone, thiazoline, thiazolidine, morpholine,oxirane, piperidine N-Oxide, piperidine, piperazine, pyrrolidine,pyrrolidone, pyrrolidione, 4-piperidone, pyrazoline, pyrazolidine,2-oxopyrrolidine, tetrahydropyran, 4H-pyran, tetrahydrothiopyran,thiamorpholine, thiamorpholine sulfoxide, thiamorpholine sulfone, andtheir benzo-fused analogs (e.g., benzimidazolidinone,tetrahydroquinoline, and 3,4-methylenedioxyphenyl).

As used herein, “aralkyl” and “aryl(alkyl)” refer to an aryl groupconnected, as a substituent, via a lower alkylene group. The loweralkylene and aryl group of an aralkyl may be substituted orunsubstituted. Examples include but are not limited to benzyl,2-phenylalkyl, 3-phenylalkyl, and naphthylalkyl.

As used herein, “heteroaralkyl” and “heteroaryl(alkyl)” refer to aheteroaryl group connected, as a substituent, via a lower alkylenegroup. The lower alkylene and heteroaryl group of heteroaralkyl may besubstituted or unsubstituted. Examples include but are not limited to2-thienylalkyl, 3-thienylalkyl, furylalkyl, thienylalkyl, pyrrolylalkyl,pyridylalkyl, isoxazolylalkyl, imidazolylalkyl, and their benzo-fusedanalogs.

A “(heteroalicyclyl)alkyl” and “(heterocyclyl)alkyl” refer to aheterocyclic or a heteroalicyclylic group connected, as a substituent,via a lower alkylene group. The lower alkylene and heterocyclyl of a(heteroalicyclyl)alkyl may be substituted or unsubstituted. Examplesinclude but are not limited tetrahydro-2H-pyran-4-yl)methyl,(piperidin-4-yl)ethyl, (piperidin-4-yl)propyl,(tetrahydro-2H-thiopyran-4-yl)methyl, and (1,3-thiazinan-4-yl)methyl.

“Lower alkylene groups” are straight-chained —CH₂— tethering groups,forming bonds to connect molecular fragments via their terminal carbonatoms. Examples include but are not limited to methylene (—CH₂—),ethylene (—CH₂CH₂—), propylene (—CH₂CH₂CH₂—), and butylene(—CH₂CH₂CH₂CH₂—). A lower alkylene group can be substituted by replacingone or more hydrogen of the lower alkylene group with a substituent(s)listed under the definition of “substituted.”

As used herein, “alkoxy” refers to the formula —OR wherein R is analkyl, an alkenyl, an alkynyl, a cycloalkyl, a cycloalkenyl, acycloalkynyl, aryl, heteroaryl, heteroalicyclyl, aralkyl,(heteroaryl)alkyl or (heteroalicyclyl)alkyl is defined herein. Anon-limiting list of alkoxys are methoxy, ethoxy, n-propoxy,1-methylethoxy (isopropoxy), n-butoxy, iso-butoxy, sec-butoxy,tert-butoxy, phenoxy and benzoxy. An alkoxy may be substituted orunsubstituted.

As used herein, “acyl” refers to a hydrogen, alkyl, alkenyl, alkynyl, oraryl connected, as substituents, via a carbonyl group. Examples includeformyl, acetyl, propanoyl, benzoyl, and acryl. An acyl may besubstituted or unsubstituted.

As used herein, “hydroxyalkyl” refers to an alkyl group in which one ormore of the hydrogen atoms are replaced by a hydroxy group. Exemplaryhydroxyalkyl groups include but are not limited to, 2-hydroxyethyl,3-hydroxypropyl, 2-hydroxypropyl, and 2,2-dihydroxyethyl. A hydroxyalkylmay be substituted or unsubstituted.

As used herein, “haloalkyl” refers to an alkyl group in which one ormore of the hydrogen atoms are replaced by a halogen (e.g.,mono-haloalkyl, di-haloalkyl and tri-haloalkyl). Such groups include butare not limited to, chloromethyl, fluoromethyl, difluoromethyl,trifluoromethyl, 1-chloro-2-fluoromethyl and 2-fluoroisobutyl. Ahaloalkyl may be substituted or unsubstituted.

As used herein, “haloalkoxy” refers to an alkoxy group in which one ormore of the hydrogen atoms are replaced by a halogen (e.g.,mono-haloalkoxy, di-haloalkoxy and tri-haloalkoxy). Such groups includebut are not limited to, chloromethoxy, fluoromethoxy, difluoromethoxy,trifluoromethoxy, 1-chloro-2-fluoromethoxy and 2-fluoroisobutoxy. Ahaloalkoxy may be substituted or unsubstituted.

As used herein, “arylthio” refers to RS—, in which R is an aryl, suchas, but not limited to, phenyl. An arylthio may be substituted orunsubstituted.

A “sulfenyl” group refers to an “—SR” group in which R can be hydrogen,alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, cycloalkynyl, aryl,heteroaryl, heteroalicyclyl, aralkyl, (heteroaryl)alkyl or(heteroalicyclyl)alkyl. A sulfenyl may be substituted or unsubstituted.

A “sulfinyl” group refers to an “—S(═O)—R” group in which R can be thesame as defined with respect to sulfenyl. A sulfinyl may be substitutedor unsubstituted.

A “sulfonyl” group refers to an “SO₂R” group in which R can be the sameas defined with respect to sulfenyl. A sulfonyl may be substituted orunsubstituted.

An “O-carboxy” group refers to a “RC(═O)O—” group in which R can behydrogen, alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl,cycloalkynyl, aryl, heteroaryl, heteroalicyclyl, aralkyl,(heteroaryl)alkyl or (heteroalicyclyl)alkyl, as defined herein. AnO-carboxy may be substituted or unsubstituted.

The terms “ester” and “C-carboxy” refer to a “—C(═O)OR” group in which Rcan be the same as defined with respect to O-carboxy. An ester andC-carboxy may be substituted or unsubstituted.

A “thiocarbonyl” group refers to a “—C(═S)R” group in which R can be thesame as defined with respect to O-carboxy. A thiocarbonyl may besubstituted or unsubstituted.

A “trihalomethanesulfonyl” group refers to an “X₃CSO₂—” group whereineach X is a halogen.

A “trihalomethanesulfonamido” group refers to an “X₃CS(O)₂N(R_(A))—”group wherein each X is a halogen, and R_(A) hydrogen, alkyl, alkenyl,alkynyl, cycloalkyl, cycloalkenyl, cycloalkynyl, aryl, heteroaryl,heteroalicyclyl, aralkyl, (heteroaryl)alkyl or (heteroalicyclyl)alkyl.

The term “amino” as used herein refers to a —NH₂ group.

As used herein, the term “hydroxy” refers to a —OH group.

A “cyano” group refers to a “—CN” group.

The term “azido” as used herein refers to a —N₃ group.

An “isocyanato” group refers to a “—NCO” group.

A “thiocyanato” group refers to a “—CNS” group.

An “isothiocyanato” group refers to an “—NCS” group.

A “mercapto” group refers to an “—SH” group.

A “carbonyl” group refers to a C═O group.

An “S-sulfonamido” group refers to a “—SO₂N(R_(A)R_(B))” group in whichR_(A) and R_(B) can be independently hydrogen, alkyl, alkenyl, alkynyl,cycloalkyl, cycloalkenyl, cycloalkynyl, aryl, heteroaryl,heteroalicyclyl, aralkyl, (heteroaryl)alkyl or (heteroalicyclyl)alkyl.An S-sulfonamido may be substituted or unsubstituted.

An “N-sulfonamido” group refers to a “RSO₂N(R_(A))—” group in which Rand R_(A) can be independently hydrogen, alkyl, alkenyl, alkynyl,cycloalkyl, cycloalkenyl, cycloalkynyl, aryl, heteroaryl,heteroalicyclyl, aralkyl, (heteroaryl)alkyl or (heteroalicyclyl)alkyl.An N-sulfonamido may be substituted or unsubstituted.

An “O-carbamyl” group refers to a “—OC(═O)N(R_(A)R_(B))” group in whichR_(A) and R_(B) can be independently hydrogen, alkyl, alkenyl, alkynyl,cycloalkyl, cycloalkenyl, cycloalkynyl, aryl, heteroaryl,heteroalicyclyl, aralkyl, (heteroaryl)alkyl or (heteroalicyclyl)alkyl.An O-carbamyl may be substituted or unsubstituted.

An “N-carbamyl” group refers to an “ROC(═O)N(R_(A))—” group in which Rand R_(A) can be independently hydrogen, alkyl, alkenyl, alkynyl,cycloalkyl, cycloalkenyl, cycloalkynyl, aryl, heteroaryl,heteroalicyclyl, aralkyl, (heteroaryl)alkyl or (heteroalicyclyl)alkyl.An N-carbamyl may be substituted or unsubstituted.

An “O-thiocarbamyl” group refers to a “—OC(═S)—N(R_(A)R_(B))” group inwhich R_(A) and R_(B) can be independently hydrogen, alkyl, alkenyl,alkynyl, cycloalkyl, cycloalkenyl, cycloalkynyl, aryl, heteroaryl,heteroalicyclyl, aralkyl, (heteroaryl)alkyl or (heteroalicyclyl)alkyl.An O-thiocarbamyl may be substituted or unsubstituted.

An “N-thiocarbamyl” group refers to an “ROC(═S)N(R_(A))—” group in whichR and R_(A) can be independently hydrogen, alkyl, alkenyl, alkynyl,cycloalkyl, cycloalkenyl, cycloalkynyl, aryl, heteroaryl,heteroalicyclyl, aralkyl, (heteroaryl)alkyl or (heteroalicyclyl)alkyl.An N-thiocarbamyl may be substituted or unsubstituted.

A “C-amido” group refers to a “—C(═O)N(R_(A)R_(B))” group in which R_(A)and R_(B) can be independently hydrogen, alkyl, alkenyl, alkynyl,cycloalkyl, cycloalkenyl, cycloalkynyl, aryl, heteroaryl,heteroalicyclyl, aralkyl, (heteroaryl)alkyl or (heteroalicyclyl)alkyl. AC-amido may be substituted or unsubstituted.

An “N-amido” group refers to a “RC(═O)N(R_(A))—” group in which R andR_(A) can be independently hydrogen, alkyl, alkenyl, alkynyl,cycloalkyl, cycloalkenyl, cycloalkynyl, aryl, heteroaryl,heteroalicyclyl, aralkyl, (heteroaryl)alkyl or (heteroalicyclyl)alkyl.An N-amido may be substituted or unsubstituted.

The term “halogen atom” or “halogen” as used herein, means any one ofthe radio-stable atoms of column 7 of the Periodic Table of theElements, such as, fluorine, chlorine, bromine and iodine.

Where the numbers of substituents is not specified (e.g. haloalkyl),there may be one or more substituents present. For example “haloalkyl”may include one or more of the same or different halogens. As anotherexample, “C₁-C₃ alkoxyphenyl” may include one or more of the same ordifferent alkoxy groups containing one, two or three atoms.

As used herein, the abbreviations for any protective groups, amino acidsand other compounds, are, unless indicated otherwise, in accord withtheir common usage, recognized abbreviations, or the IUPAC-IUBCommission on Biochemical Nomenclature (See, Biochem. 11:942-944(1972)).

The term “nucleoside” is used herein in its ordinary sense as understoodby those skilled in the art, and refers to a compound composed of anoptionally substituted pentose moiety or modified pentose moietyattached to a heterocyclic base or tautomer thereof via a N-glycosidicbond, such as attached via the 9-position of a purine-base or the1-position of a pyrimidine-base. Examples include, but are not limitedto, a ribonucleoside comprising a ribose moiety and adeoxyribonucleoside comprising a deoxyribose moiety. A modified pentosemoiety is a pentose moiety in which an oxygen atom has been replacedwith a carbon and/or a carbon has been replaced with a sulfur or anoxygen atom. A “nucleoside” is a monomer that can have a substitutedbase and/or sugar moiety. Additionally, a nucleoside can be incorporatedinto larger DNA and/or RNA polymers and oligomers. In some instances,the nucleoside can be a nucleoside analog drug.

The term “nucleotide” is used herein in its ordinary sense as understoodby those skilled in the art, and refers to a nucleoside having aphosphate ester bound to the pentose moiety, for example, at the5′-position.

As used herein, the term “heterocyclic base” refers to an optionallysubstituted nitrogen-containing heterocyclyl that can be attached to anoptionally substituted pentose moiety or modified pentose moiety. Insome embodiments, the heterocyclic base can be selected from anoptionally substituted purine-base, an optionally substitutedpyrimidine-base and an optionally substituted triazole-base (forexample, a 1,2,4-triazole). The term “purine-base” is used herein in itsordinary sense as understood by those skilled in the art, and includesits tautomers. Similarly, the term “pyrimidine-base” is used herein inits ordinary sense as understood by those skilled in the art, andincludes its tautomers. A non-limiting list of optionally substitutedpurine-bases includes purine, adenine, guanine, hypoxanthine, xanthine,alloxanthine, 7-alkylguanine (e.g. 7-methylguanine), theobromine,caffeine, uric acid and isoguanine. Examples of pyrimidine-basesinclude, but are not limited to, cytosine, thymine, uracil,5,6-dihydrouracil and 5-alkylcytosine (e.g., 5-methylcytosine). Anexample of an optionally substituted triazole-base is1,2,4-triazole-3-carboxamide. Other non-limiting examples ofheterocyclic bases include diaminopurine, 8-oxo-N⁶-alkyladenine (e.g.,8-oxo-N⁶-methyladenine), 7-deazaxanthine, 7-deazaguanine,7-deazaadenine, N⁴,N⁴-ethanocytosin, N⁶,N⁶-ethano-2,6-diaminopurine,5-halouracil (e.g., 5-fluorouracil and 5-bromouracil),pseudoisocytosine, isocytosine, isoguanine, and other heterocyclic basesdescribed in U.S. Pat. Nos. 5,432,272 and 7,125,855, which areincorporated herein by reference for the limited purpose of disclosingadditional heterocyclic bases. In some embodiments, a heterocyclic basecan be optionally substituted with an amine or an enol protectinggroup(s).

The term “—N-linked amino acid” refers to an amino acid that is attachedto the indicated moiety via a main-chain amino or mono-substituted aminogroup. When the amino acid is attached in an —N-linked amino acid, oneof the hydrogens that is part of the main-chain amino ormono-substituted amino group is not present and the amino acid isattached via the nitrogen. N-linked amino acids can be substituted orunsubstituted.

The term “—N-linked amino acid ester derivative” refers to an amino acidin which a main-chain carboxylic acid group has been converted to anester group. In some embodiments, the ester group has a formula selectedfrom alkyl-O—C(═O)—, cycloalkyl-O—C(═O)—, aryl-O—C(═O)— andaryl(alkyl)-O—C(═O)—. A non-limiting list of ester groups includesubstituted and unsubstituted versions of the following:methyl-O—C(═O)—, ethyl-O—C(═O)—, n-propyl-O—C(═O)—, isopropyl-O—C(═O)—,n-butyl-O—C(═O)—, isobutyl-O—C(═O)—, tert-butyl-O—C(═O)—,neopentyl-O—C(═O)—, cyclopropyl-O—C(═O)—, cyclobutyl-O—C(═O)—,cyclopentyl-O—C(═O)—, cyclohexyl-O—C(═O)—, phenyl-O—C(═O)—,benzyl-O—C(═O)—, and naphthyl-O—C(═O)—. N-linked amino acid esterderivatives can be substituted or unsubstituted.

The term “—O-linked amino acid” refers to an amino acid that is attachedto the indicated moiety via the hydroxy from its main-chain carboxylicacid group. When the amino acid is attached in an —O-linked amino acid,the hydrogen that is part of the hydroxy from its main-chain carboxylicacid group is not present and the amino acid is attached via the oxygen.O-linked amino acids can be substituted or unsubstituted.

As used herein, the term “amino acid” refers to any amino acid (bothstandard and non-standard amino acids), including, but not limited to,α-amino acids, β-amino acids, γ-amino acids and δ-amino acids. Examplesof suitable amino acids include, but are not limited to, alanine,asparagine, aspartate, cysteine, glutamate, glutamine, glycine, proline,serine, tyrosine, arginine, histidine, isoleucine, leucine, lysine,methionine, phenylalanine, threonine, tryptophan and valine. Additionalexamples of suitable amino acids include, but are not limited to,ornithine, hypusine, 2-aminoisobutyric acid, dehydroalanine,gamma-aminobutyric acid, citrulline, beta-alanine, alpha-ethyl-glycine,alpha-propyl-glycine and norleucine.

The terms “phosphorothioate” and “phosphothioate” refer to a compound ofthe general formula

its protonated forms (for example,

and its tautomers (such as

As used herein, the term “phosphate” is used in its ordinary sense asunderstood by those skilled in the art, and includes its protonatedforms (for example,

As used herein, the terms “monophosphate,” “diphosphate,” and“triphosphate” are used in their ordinary sense as understood by thoseskilled in the art, and include protonated forms.

The terms “protecting group” and “protecting groups” as used hereinrefer to any atom or group of atoms that is added to a molecule in orderto prevent existing groups in the molecule from undergoing unwantedchemical reactions. Examples of protecting group moieties are describedin T. W. Greene and P. G. M. Wuts, Protective Groups in OrganicSynthesis, 3. Ed. John Wiley & Sons, 1999, and in J. F. W. McOmie,Protective Groups in Organic Chemistry Plenum Press, 1973, both of whichare hereby incorporated by reference for the limited purpose ofdisclosing suitable protecting groups. The protecting group moiety maybe chosen in such a way, that they are stable to certain reactionconditions and readily removed at a convenient stage using methodologyknown from the art. A non-limiting list of protecting groups includebenzyl; substituted benzyl; alkylcarbonyls and alkoxycarbonyls (e.g.,t-butoxycarbonyl (BOC), acetyl, or isobutyryl); arylalkylcarbonyls andarylalkoxycarbonyls (e.g., benzyloxycarbonyl); substituted methyl ether(e.g. methoxymethyl ether); substituted ethyl ether; a substitutedbenzyl ether; tetrahydropyranyl ether; silyls (e.g., trimethylsilyl,triethylsilyl, triisopropylsilyl, t-butyldimethylsilyl,tri-iso-propylsilyloxymethyl, [2-(trimethylsilyl)ethoxy]methyl ort-butyldiphenylsilyl); esters (e.g. benzoate ester); carbonates (e.g.methoxymethylcarbonate); sulfonates (e.g. tosylate or mesylate); acyclicketal (e.g. dimethyl acetal); cyclic ketals (e.g., 1,3-dioxane,1,3-dioxolanes, and those described herein); acyclic acetal; cyclicacetal (e.g., those described herein); acyclic hemiacetal; cyclichemiacetal; cyclic dithioketals (e.g., 1,3-dithiane or 1,3-dithiolane);orthoesters (e.g., those described herein) and triarylmethyl groups(e.g., trityl; monomethoxytrityl (MMTr); 4,4′-dimethoxytrityl (DMTr);4,4′,4″-trimethoxytrityl (TMTr); and those described herein).

The term “pharmaceutically acceptable salt” refers to a salt of acompound that does not cause significant irritation to an organism towhich it is administered and does not abrogate the biological activityand properties of the compound. In some embodiments, the salt is an acidaddition salt of the compound. Pharmaceutical salts can be obtained byreacting a compound with inorganic acids such as hydrohalic acid (e.g.,hydrochloric acid or hydrobromic acid), sulfuric acid, nitric acid andphosphoric acid. Pharmaceutical salts can also be obtained by reacting acompound with an organic acid such as aliphatic or aromatic carboxylicor sulfonic acids, for example formic, acetic, succinic, lactic, malic,tartaric, citric, ascorbic, nicotinic, methanesulfonic, ethanesulfonic,p-toluensulfonic, salicylic or naphthalenesulfonic acid. Pharmaceuticalsalts can also be obtained by reacting a compound with a base to form asalt such as an ammonium salt, an alkali metal salt, such as a sodium ora potassium salt, an alkaline earth metal salt, such as a calcium or amagnesium salt, a salt of organic bases such as dicyclohexylamine,N-methyl-D-glucamine, tris(hydroxymethyl)methylamine, C₁-C₇ alkylamine,cyclohexylamine, triethanolamine, ethylenediamine, and salts with aminoacids such as arginine and lysine.

Terms and phrases used in this application, and variations thereof,especially in the appended claims, unless otherwise expressly stated,should be construed as open ended as opposed to limiting. As examples ofthe foregoing, the term ‘including’ should be read to mean ‘including,without limitation,’ ‘including but not limited to,’ or the like; theterm ‘comprising’ as used herein is synonymous with ‘including,’‘containing,’ or ‘characterized by,’ and is inclusive or open-ended anddoes not exclude additional, unrecited elements or method steps; theterm ‘having’ should be interpreted as ‘having at least;’ the term‘includes’ should be interpreted as ‘includes but is not limited to;’the term ‘example’ is used to provide exemplary instances of the item indiscussion, not an exhaustive or limiting list thereof; and use of termslike ‘preferably,’ preferred, ‘desired,’ or ‘desirable,’ and words ofsimilar meaning should not be understood as implying that certainfeatures are critical, essential, or even important to the structure orfunction of the invention, but instead as merely intended to highlightalternative or additional features that may or may not be utilized in aparticular embodiment. In addition, the term “comprising” is to beinterpreted synonymously with the phrases “having at least” or“including at least”. When used in the context of a process, the term“comprising” means that the process includes at least the recited steps,but may include additional steps. When used in the context of acompound, composition or device, the term “comprising” means that thecompound, composition or device includes at least the recited featuresor components, but may also include additional features or components.Likewise, a group of items linked with the conjunction ‘and’ should notbe read as requiring that each and every one of those items be presentin the grouping, but rather should be read as ‘and/or’ unless expresslystated otherwise. Similarly, a group of items linked with theconjunction ‘or’ should not be read as requiring mutual exclusivityamong that group, but rather should be read as ‘and/or’ unless expresslystated otherwise.

With respect to the use of substantially any plural and/or singularterms herein, those having skill in the art can translate from theplural to the singular and/or from the singular to the plural as isappropriate to the context and/or application. The varioussingular/plural permutations may be expressly set forth herein for sakeof clarity. The indefinite article “a” or “an” does not exclude aplurality. A single processor or other unit may fulfill the functions ofseveral items recited in the claims. The mere fact that certain measuresare recited in mutually different dependent claims does not indicatethat a combination of these measures cannot be used to advantage. Anyreference signs in the claims should not be construed as limiting thescope.

It is understood that, in any compound described herein having one ormore chiral centers, if an absolute stereochemistry is not expresslyindicated, then each center may independently be of R-configuration orS-configuration or a mixture thereof. Thus, the compounds providedherein may be enantiomerically pure, enantiomerically enriched, racemicmixture, diastereomerically pure, diastereomerically enriched, or astereoisomeric mixture. In addition it is understood that, in anycompound described herein having one or more double bond(s) generatinggeometrical isomers that can be defined as E or Z, each double bond mayindependently be E or Z a mixture thereof.

Likewise, it is understood that, in any compound described, alltautomeric forms are also intended to be included. For example alltautomers of a phosphate and a phosphorothioate groups are intended tobe included. Examples of tautomers of a phosphorothioate include thefollowing:

Furthermore, all tautomers of heterocyclic bases known in the art areintended to be included, including tautomers of natural and non-naturalpurine-bases and pyrimidine-bases.

It is to be understood that where compounds disclosed herein haveunfilled valencies, then the valencies are to be filled with hydrogensor isotopes thereof, e.g., hydrogen-1 (protium) and hydrogen-2(deuterium).

It is understood that the compounds described herein can be labeledisotopically. Substitution with isotopes such as deuterium may affordcertain therapeutic advantages resulting from greater metabolicstability, such as, for example, increased in vivo half-life or reduceddosage requirements. Each chemical element as represented in a compoundstructure may include any isotope of said element. For example, in acompound structure a hydrogen atom may be explicitly disclosed orunderstood to be present in the compound. At any position of thecompound that a hydrogen atom may be present, the hydrogen atom can beany isotope of hydrogen, including but not limited to hydrogen-1(protium) and hydrogen-2 (deuterium). Thus, reference herein to acompound encompasses all potential isotopic forms unless the contextclearly dictates otherwise.

It is understood that the methods and combinations described hereininclude crystalline forms (also known as polymorphs, which include thedifferent crystal packing arrangements of the same elemental compositionof a compound), amorphous phases, salts, solvates, and hydrates. In someembodiments, the compounds described herein exist in solvated forms withpharmaceutically acceptable solvents such as water, ethanol, or thelike. In other embodiments, the compounds described herein exist inunsolvated form. Solvates contain either stoichiometric ornon-stoichiometric amounts of a solvent, and may be formed during theprocess of crystallization with pharmaceutically acceptable solventssuch as water, ethanol, or the like. Hydrates are formed when thesolvent is water, or alcoholates are formed when the solvent is alcohol.In addition, the compounds provided herein can exist in unsolvated aswell as solvated forms. In general, the solvated forms are consideredequivalent to the unsolvated forms for the purposes of the compounds andmethods provided herein.

Where a range of values is provided, it is understood that the upper andlower limit, and each intervening value between the upper and lowerlimit of the range is encompassed within the embodiments.

Compounds

Some embodiments disclosed herein relate to a compound selected fromFormula (I), Formula (II) and Formula (III), or a pharmaceuticallyacceptable salt of the foregoing:

wherein: B^(1A), B^(1B) and B^(1C) can be independently an optionallysubstituted heterocyclic base or an optionally substituted heterocyclicbase with a protected amino group; R^(1A) can be selected from hydrogen,an optionally substituted acyl, an optionally substituted O-linked aminoacid,

when the dashed line (------) of Formula (I) is a single bond, R^(2A)can be CH₂, and R^(3A) can be O (oxygen); when the dashed line (------)of Formula (I) is absent, R^(2A) can be selected from an optionallysubstituted C₁₋₆ alkyl, an optionally substituted C₂₋₆ alkenyl, anoptionally substituted C₂₋₆ alkynyl, an optionally substituted C₃₋₆cycloalkyl, an optionally substituted —O—C₁₋₆ alkyl, an optionallysubstituted O—C₃₋₆ alkenyl, an optionally substituted O—C₃₋₆ alkenyl andcyano, and R^(3A) can be selected from OH, —OC(═O)R″^(A) and anoptionally substituted O-linked amino acid; R^(1B) can be selected fromO⁻, OH,

an optionally substituted N-linked amino acid and an optionallysubstituted N-linked amino acid ester derivative; R^(1C) and R^(2C) canbe independently selected from O⁻, OH, an optionally substituted C₁₋₆alkoxy,

an optionally substituted N-linked amino acid and an optionallysubstituted N-linked amino acid ester derivative; or R^(1C) can be

and R^(2C) can be O⁻ or OH; R^(2B) and R^(3C) can be independentlyselected from an optionally substituted C₁₋₆ alkyl, an optionallysubstituted C₂₋₆ alkenyl, an optionally substituted C₂₋₆ alkynyl, anoptionally substituted —O—C₁₋₆ alkyl, an optionally substituted —O—C₃₋₆alkenyl, an optionally substituted —O—C₃₋₆ alkynyl, an optionallysubstituted C₃₋₆ cycloalkyl and cyano; R^(4C) can be selected from OH,—OC(═O)R″^(C) and an optionally substituted O-linked amino acid; R^(4A),R^(3B) and R^(5C) can be independently a halogen; R^(5A), R^(4B) andR^(6C) can be independently hydrogen or halogen; R^(6A), R^(7A) andR^(8A) can be independently selected from absent, hydrogen, anoptionally substituted C₁₋₂₄ alkyl, an optionally substituted C₂₋₂₄alkenyl, an optionally substituted C₂₋₂₄ alkynyl, an optionallysubstituted C₃₋₆ cycloalkyl, an optionally substituted C₃₋₆cycloalkenyl, an optionally substituted aryl, an optionally substitutedheteroaryl, an optionally substituted aryl(C₁₋₆ alkyl), an optionallysubstituted *—(CR^(15A)R^(16A))_(p)—O—C₁₋₂₄ alkyl, an optionallysubstituted *—(CR^(17A)R^(18A))_(q)—O—C₁₋₂₄ alkenyl,

can be

and R^(7A) can be absent or hydrogen; or R^(6A) and R^(7A) can be takentogether to form a moiety selected from an optionally substituted

and an optionally substituted

wherein the oxygens connected to R^(6A) and R^(7A), the phosphorus andthe moiety form a six-membered to ten-membered ring system; R^(9A) canbe independently selected from an optionally substituted C₁₋₂₄ alkyl, anoptionally substituted C₂₋₂₄ alkenyl, an optionally substituted C₂₋₂₄alkynyl, an optionally substituted C₃₋₆ cycloalkyl, an optionallysubstituted C₃₋₆ cycloalkenyl, NR^(30A)R^(31A), an optionallysubstituted N-linked amino acid and an optionally substituted N-linkedamino acid ester derivative; R^(10A) and R^(11A) can be independently anoptionally substituted N-linked amino acid or an optionally substitutedN-linked amino acid ester derivative; R^(12A), R^(13A) and R^(14A) canbe independently absent or hydrogen; each R^(15A), each R^(16A), eachR^(17A) and each R^(18A) can be independently hydrogen, an optionallysubstituted C₁₋₂₄ alkyl or alkoxy; R^(19A), R^(20A), R^(22A), R^(23A),R^(5B), R^(6B), R^(8B), R^(9B), R^(9C), R^(10C), R^(12C) and R^(13C) canbe independently selected from hydrogen, an optionally substituted C₁₋₂₄alkyl and an optionally substituted aryl; R^(21A), R^(24A), R^(7B),R^(10B), R^(11C) and R^(14C) can be independently selected fromhydrogen, an optionally substituted C₁₋₂₄ alkyl, an optionallysubstituted aryl, an optionally substituted —O—C₁₋₂₄ alkyl and anoptionally substituted —O-aryl; R^(25A), R^(29A), R^(11B) and R^(15C)can be independently selected from hydrogen, an optionally substitutedC₁₋₂₄ alkyl and an optionally substituted aryl; R^(16C), R^(17C) andR^(18C) can be independently absent or hydrogen; R^(26A) and R^(27A) canbe independently —C≡N or an optionally substituted substituent selectedfrom C₂₋₈ organylcarbonyl, C₂₋₈ alkoxycarbonyl and C₂₋₈organylaminocarbonyl; R^(28A) can be selected from hydrogen, anoptionally substituted C₁₋₂₄-alkyl, an optionally substituted C₂₋₂₄alkenyl, an optionally substituted C₂₋₂₄ alkynyl, an optionallysubstituted C₃₋₆ cycloalkyl and an optionally substituted C₃₋₆cycloalkenyl; R^(30A) and R^(31A) can be independently selected fromhydrogen, an optionally substituted C₁₋₂₄-alkyl, an optionallysubstituted C₂₋₂₄ alkenyl, an optionally substituted C₂₋₂₄ alkynyl, anoptionally substituted C₃₋₆ cycloalkyl and an optionally substitutedC₃₋₆ cycloalkenyl; for Formula (III), ------- can be a single bond or adouble bond; when ------- is a single bond, each R^(7C) and each R^(8C)can be independently hydrogen or halogen; and when ------- is a doublebond, each R^(7C) is absent and each R^(8C) can be independentlyhydrogen or halogen; R″^(A) and R″^(C) can be independently anoptionally substituted C₁₋₂₄-alkyl, m and n can be independently 0 or 1;p and q can be independently selected from 1, 2 and 3; r can be 1 or 2;Z^(1A), Z^(2A), Z^(3A), Z^(4A), Z^(1B), Z^(2B) and Z^(1C) can beindependently O or S; and provided that when the dashed line (------) ofFormula (I) is absent; R^(1A) is

wherein R^(8A) is an unsubstituted C₁₋₄ alkyl or phenyl optionallypara-substituted with a halogen or methyl and R^(9A) is methyl ester,ethyl ester, isopropyl ester, n-butyl ester, benzyl ester or phenylester of an amino acid selected from glycine, alanine, valine, leucine,phenylalanine, tryptophan, methionine and proline; R^(3A) is OH; R^(4A)is fluoro; R^(5A) is fluoro or hydrogen; and B^(1A) is an unsubstituteduracil; then R^(2A) cannot be —OCH₃; provided that when the dashed line(------) of Formula (I) is absent; R^(1A) is H; R^(3A) is OH; R^(4A) isfluoro; R^(5A) is fluoro; and B^(1A) is an unsubstituted cytosine; thenR^(2A) cannot be allenyl; provided that when the dashed line (------) ofFormula (I) is absent; R^(1A) is H; R^(3A) is OH; R^(4A) is fluoro;R^(5A) is hydrogen; and B^(1A) is an unsubstituted thymine; then R^(2A)cannot be C₁ alkyl substituted with an optionally substituted N-amido(for example, —NC(═O)CF₃); and provided that when the dashed line(------) of Formula (I) is absent; R^(1A) is H; R^(3A) is OH; R^(4A) isfluoro; R^(5A) is fluoro; and B^(1A) is an unsubstituted cytosine; thenR^(2A) cannot be ethynyl.

In some embodiments, the compound can be a compound of Formula (I), or apharmaceutically acceptable salt thereof, wherein: B^(1A) can be anoptionally substituted heterocyclic base or an optionally substitutedheterocyclic base with a protected amino group; R^(1A) can be selectedfrom hydrogen,

when the dashed line (------) of Formula (I) is a single bond, R^(2A) isCH₂, and R^(3A) is O (oxygen); when the dashed line (------) of Formula(I) is absent, R^(2A) can be selected from an optionally substitutedC₁₋₆ alkyl, an optionally substituted C₂₋₆ alkenyl, an optionallysubstituted C₂₋₆ alkynyl, an optionally substituted —O—C₁₋₆ alkyl, anoptionally substituted —O—C₃₋₆ alkenyl, an optionally substituted—O—C₃₋₆ alkynyl and cyano, and R^(3A) is OH; R^(4A) can be a halogen;R^(5A) can be hydrogen or halogen; R^(6A), R^(7A) and R^(8A) can beindependently selected from absent, hydrogen, an optionally substitutedC₁₋₂₄ alkyl, an optionally substituted C₂₋₂₄ alkenyl, an optionallysubstituted C₂₋₂₄ alkynyl, an optionally substituted C₃₋₆ cycloalkyl, anoptionally substituted C₃₋₆ cycloalkenyl, an optionally substitutedaryl, an optionally substituted heteroaryl, an optionally substitutedaryl(C₁₋₆ alkyl), an optionally substituted*—(CR^(15A)R^(16A))_(p)—O—C₁₋₂₄ alkyl, an optionally substituted*—(CR^(17A)R^(18A))_(q)—O—C₁₋₂₄ alkenyl,

or R^(6A) can be

and R^(7A) can be absent or hydrogen; or R^(6A) and R^(7A) can be takentogether to form a moiety selected from an optionally substituted

and an optionally substituted

wherein the oxygens connected to R^(6A) and R^(7A), the phosphorus andthe moiety form a six-membered to ten-membered ring system. R^(9A) canbe independently selected from an optionally substituted C₁₋₂₄ alkyl, anoptionally substituted C₂₋₂₄ alkenyl, an optionally substituted C₂₋₂₄alkynyl, an optionally substituted C₃₋₆ cycloalkyl, an optionallysubstituted C₃₋₆ cycloalkenyl, NR^(30A)R^(31A), an optionallysubstituted N-linked amino acid and an optionally substituted N-linkedamino acid ester derivative; R^(10A) and R^(11A) can be independently anoptionally substituted N-linked amino acid or an optionally substitutedN-linked amino acid ester derivative; R^(12A), R^(13A) and R^(14A) canbe independently absent or hydrogen; each R^(15A), each R^(16A), eachR^(17A) and each R^(18A) can be independently hydrogen, an optionallysubstituted C₁₋₂₄ alkyl or alkoxy; R^(19A), R^(20A), R^(22A) and R^(23A)can be independently selected from hydrogen, an optionally substitutedC₁₋₂₄ alkyl and an optionally substituted aryl; R^(21A) and R^(24A) canbe independently selected from hydrogen, an optionally substituted C₁₋₂₄alkyl, an optionally substituted aryl, an optionally substituted—O—C₁₋₂₄ alkyl and an optionally substituted —O-aryl; R^(25A) andR^(29A) can be independently selected from hydrogen, an optionallysubstituted C₁₋₂₄ alkyl and an optionally substituted aryl; R^(26A) andR^(27A) can be independently —C≡N or an optionally substitutedsubstituent selected from C₂₋₈ organylcarbonyl, C₂₋₈ alkoxycarbonyl andC₂₋₈ organylaminocarbonyl; R^(28A) can be selected from hydrogen, anoptionally substituted C₁₋₂₄-alkyl, an optionally substituted C₂₋₂₄alkenyl, an optionally substituted C₂₋₂₄ alkynyl, an optionallysubstituted C₃₋₆ cycloalkyl and an optionally substituted C₃₋₆cycloalkenyl; R^(30A) and R^(31A) can be independently selected fromhydrogen, an optionally substituted C₁₋₂₄-alkyl, an optionallysubstituted C₂₋₂₄ alkenyl, an optionally substituted C₂₋₂₄ alkynyl, anoptionally substituted C₃₋₆ cycloalkyl and an optionally substitutedC₃₋₆ cycloalkenyl; m can be 0 or 1; p and q can be independentlyselected from 1, 2 and 3; r can be 1 or 2; Z^(1A), Z^(2A), Z^(3A) andZ^(4A) can be independently O or S. In some embodiments, a compound ofFormula (I) can have a structure shown herein, provided that when thedashed line (------) of Formula (I) is absent; R^(1A) is

wherein R^(8A) is an unsubstituted C₁₋₄ alkyl or phenyl optionallypara-substituted with a halogen or methyl and R^(9A) is methyl ester,ethyl ester, isopropyl ester, n-butyl ester, benzyl ester or phenylester of an amino acid selected from glycine, alanine, valine, leucine,phenylalanine, tryptophan, methionine and proline; R^(3A) is OH; R^(4A)is fluoro; R^(5A) is fluoro or hydrogen; and B^(1A) is an unsubstituteduracil; then R^(2A) cannot be —OCH₃; provided that when the dashed line(------) of Formula (I) is absent; R^(1A) is H; R^(3A) is OH; R^(4A) isfluoro; R^(5A) is fluoro; and B^(1A) is an unsubstituted cytosine; thenR^(2A) cannot be allenyl; provided that when the dashed line (------) ofFormula (I) is absent; R^(1A) is H; R^(3A) is OH; R^(4A) is fluoro;R^(5A) is hydrogen; and B^(1A) is an unsubstituted thymine; then R^(2A)cannot be C₁ alkyl substituted with an N-amido; and provided that whenthe dashed line (------) of Formula (I) is absent; R^(1A) is H; R^(3A)is OH; R^(4A) is fluoro; R^(5A) is fluoro; and B^(1A) is anunsubstituted cytosine; then R^(2A) cannot be ethynyl.

In some embodiments, R^(1A) can be

In some embodiments, R^(6A) and R^(7A) can be both hydrogen. In otherembodiments, R^(6A) and R^(7A) can be both absent. In still otherembodiments, at least one R^(6A) and R^(7A) can be absent. In yet stillother embodiments, at least one R^(6A) and R^(7A) can be hydrogen. Thoseskilled in the art understand that when R^(6A) and/or R^(7A) are absent,the associated oxygen(s) will have a negative charge. For example, whenR^(6A) is absent, the oxygen associated with R^(6A) will have a negativecharge. In some embodiments, Z^(1A) can be O (oxygen). In otherembodiments, Z^(1A) can be S (sulfur). In some embodiments, R^(1A) canbe a monophosphate. In other embodiments, R^(1A) can be amonothiophosphate.

In some embodiments, when R^(1A) is

one of R^(6A) and R^(7A) can be hydrogen, and the other of R^(6A) andR^(7A) is selected from an optionally substituted C₁₋₂₄ alkyl, anoptionally substituted C₂₋₂₄ alkenyl, an optionally substituted C₂₋₂₄alkynyl, an optionally substituted C₃₋₆ cycloalkyl, an optionallysubstituted C₃₋₆ cycloalkenyl, an optionally substituted aryl, anoptionally substituted heteroaryl and an optionally substitutedaryl(C₁₋₆ alkyl). In some embodiments, one of R^(6A) and R^(7A) can behydrogen, and the other of R^(6A) and R^(7A) can be an optionallysubstituted C₁₋₂₄ alkyl. In other embodiments, both R^(6A) and R^(7A)can be independently selected from an optionally substituted C₁₋₂₄alkyl, an optionally substituted C₂₋₂₄ alkenyl, an optionallysubstituted C₂₋₂₄ alkynyl, an optionally substituted C₃₋₆ cycloalkyl, anoptionally substituted C₃₋₆ cycloalkenyl, an optionally substitutedaryl, an optionally substituted heteroaryl and an optionally substitutedaryl(C₁₋₆ alkyl). In some embodiments, both R^(6A) and R^(7A) can be anoptionally substituted C₁₋₂₄ alkyl. In other embodiments, both R^(6A)and R^(7A) can be an optionally substituted C₂₋₂₄ alkenyl. In someembodiments, R^(6A) and R^(7A) can be independently an optionallysubstituted version of the following: myristoleyl, myristyl,palmitoleyl, palmityl, sapienyl, oleyl, elaidyl, vaccenyl, linoleyl,α-linolenyl, arachidonyl, eicosapentaenyl, erucyl, docosahexaenyl,caprylyl, capryl, lauryl, stearyl, arachidyl, behenyl, lignoceryl, andcerotyl.

In some embodiments, at least one of R^(6A) and R^(7A) can be*—(CR^(15A)R^(16A))_(p)—O—C₁₋₂₄ alkyl. In other embodiments, R^(6A) andR^(7A) can be both *—(CR^(15A)R^(16A))_(p)—O—C₁₋₂₄ alkyl. In someembodiments, each R^(15A) and each R^(16A) are hydrogen. In otherembodiments, at least one of R^(15A) and R^(16A) is an optionallysubstituted C₁₋₂₄ alkyl. In other embodiments, at least one of R^(15A)and R^(16A) is an alkoxy (for example, benzoxy). In some embodiments, pcan be 1. In other embodiments, p can be 2. In still other embodiments,p can be 3.

In some embodiments, at least one of R^(6A) and R^(7A) can be*—(CR^(17A)R^(18A))_(q)—O—C₂₋₂₄ alkenyl. In other embodiments, R^(6A)and R^(7A) can be both *—(CR^(17A)R^(18A))_(q)—O—C₂₋₂₄ alkenyl. In someembodiments, each R^(17A) and each R^(18A) are hydrogen. In otherembodiments, at least one of R^(17A) and R^(18A) is an optionallysubstituted C₁₋₂₄ alkyl. In some embodiments, q can be 1. In otherembodiments, q can be 2. In still other embodiments, q can be 3. When atleast one of R^(6A) and R^(7A) is *—(CR^(15A)R^(16A))_(p)—O—C₁₋₂₄ alkylor *—(CR^(17A)R^(18A))_(q)—O—C₂₋₂₄ alkenyl, the C₁₋₂₄ alkyl can beselected from caprylyl, capryl, lauryl, myristyl, palmityl, stearyl,arachidyl, behenyl, lignoceryl, and cerotyl, and the C₂₋₂₄ alkenyl canbe selected from myristoleyl, palmitoleyl, sapienyl, oleyl, elaidyl,vaccenyl, linoleyl, α-linolenyl, arachidonyl, eicosapentaenyl, erucyland docosahexaenyl.

In some embodiments, when R^(1A) is

at least one of R^(6A) and R^(7A) can be selected from

and the other of R^(6A) and R^(7A) can be selected from absent,hydrogen, an optionally substituted C₁₋₂₄ alkyl, an optionallysubstituted C₂₋₂₄ alkenyl, an optionally substituted C₂₋₂₄ alkynyl, anoptionally substituted C₃₋₆ cycloalkyl, an optionally substituted C₃₋₆cycloalkenyl, an optionally substituted aryl, an optionally substitutedheteroaryl and an optionally substituted aryl(C₁₋₆ alkyl).

In some embodiments, at least one of R^(6A) and R^(7A) can be

In some embodiments, both R^(6A) and R^(7A) can be

When one or both of R^(6A) and R^(7A) are

R^(19A) and R^(20A) can be independently selected from hydrogen, anoptionally substituted C₁₋₂₄ alkyl and an optionally substituted aryl;and R^(21A) can be selected from hydrogen, an optionally substitutedC₁₋₂₄ alkyl, an optionally substituted aryl, an optionally substituted—O—C₁₋₂₄ alkyl and an optionally substituted —O-aryl. In someembodiments, R^(19A) and R^(20A) can be hydrogen. In other embodiments,at least one of R^(19A) and R^(20A) can be an optionally substitutedC₁₋₂₄ alkyl or an optionally substituted aryl. In some embodiments,R^(21A) can be an optionally substituted C₁₋₂₄ alkyl. In otherembodiments, R^(21A) can be an optionally substituted aryl. In stillother embodiments, R^(21A) can be an optionally substituted —O—C₁₋₂₄alkyl or an optionally substituted —O-aryl.

In some embodiments, both R^(6A) and R^(7A) can be

When one or both of R^(6A) and R^(7A) are

R^(22A) and R^(23A) can be independently selected from hydrogen, anoptionally substituted C₁₋₂₄ alkyl and an optionally substituted aryl;R^(24A) can be independently selected from hydrogen, an optionallysubstituted C₁₋₂₄ alkyl, an optionally substituted aryl, an optionallysubstituted —O—C₁₋₂₄ alkyl and an optionally substituted —O-aryl; andZ^(4A) can be independently O (oxygen) or S (sulfur). In someembodiments, R^(22A) and R^(23A) can be hydrogen. In other embodiments,at least one of R^(22A) and R^(23A) can be an optionally substitutedC₁₋₂₄ alkyl or an optionally substituted aryl. In some embodiments,R^(24A) can be an optionally substituted C₁₋₂₄ alkyl. In otherembodiments, R^(24A) can be an optionally substituted aryl. In stillother embodiments, R^(24A) can be an optionally substituted —O—C₁₋₂₄alkyl or an optionally substituted —O-aryl. In some embodiments, Z^(4A)can be O (oxygen). In other embodiments, Z^(4A) can be or S (sulfur). Insome embodiments, one or both of R^(6A) and R^(7A) can beisopropylcarbonyloxymethyl. In some embodiments, one or both of R^(6A)and R^(7A) can be pivaloyloxymethyl.

In some embodiments, both R^(6A) and R^(7A) can be

When one or both of R^(6A) and R^(7A) are

R^(26A) and R^(27A) can be independently —C≡N or an optionallysubstituted substituent selected from C₂₋₈ organylcarbonyl, C₂₋₈alkoxycarbonyl and C₂₋₈ organylaminocarbonyl; R^(28A) can be selectedfrom hydrogen, an optionally substituted C₁₋₂₄-alkyl, an optionallysubstituted C₂₋₂₄ alkenyl, an optionally substituted C₂₋₂₄ alkynyl, anoptionally substituted C₃₋₆ cycloalkyl and an optionally substitutedC₃₋₆ cycloalkenyl; and r can be 1 or 2. In some embodiments, R^(26A) canbe —C≡N and R^(27A) can be an optionally substituted C₂₋₈alkoxycarbonyl, such as —C(═O)OCH₃. In other embodiments, R^(26A) can be—C≡N and R^(27A) can be an optionally substituted C₂₋₈organylaminocarbonyl, for example, —C(═O)NHCH₂CH₃ and—C(═O)NHCH₂CH₂phenyl. In some embodiments, both R^(26A) and R^(27A) canbe an optionally substituted C₂₋₈ organylcarbonyl, such as —C(═O)CH₃. Insome embodiments, both R^(26A) and R^(27A) can be an optionallysubstituted C₁₋₈ alkoxycarbonyl, for example, —C(═O)OCH₂CH₃ and—C(═O)OCH₃. In some embodiments, including those described in thisparagraph, R^(28A) can be an optionally substituted C₁₋₄-alkyl. In someembodiment, R^(28A) can be methyl or tert-butyl. In some embodiments, rcan be 1. In other embodiments, r can be 2.

Example of

include, but are not limited to the following:

In some embodiments, R^(6A) and R^(7A) can be both an optionallysubstituted aryl. In some embodiments, at least one of R^(6A) and R^(7A)can be an optionally substituted aryl. For example, both R^(6A) andR^(7A) can be an optionally substituted phenyl or an optionallysubstituted naphthyl. When substituted, the substituted aryl can besubstituted with 1, 2, 3 or more than 3 substituents. When more the twosubstituents are present, the substituents can be the same or different.In some embodiments, when at least one of R^(6A) and R^(7A) is asubstituted phenyl, the substituted phenyl can be a para-, ortho- ormeta-substituted phenyl.

In some embodiments, R^(6A) and R^(7A) can be both an optionallysubstituted aryl(C₁₋₆ alkyl). In some embodiments, at least one ofR^(6A) and R^(7A) can be an optionally substituted aryl(C₁₋₆ alkyl). Forexample, both R^(6A) and R^(7A) can be an optionally substituted benzyl.When substituted, the substituted benzyl group can be substituted with1, 2, 3 or more than 3 substituents. When more the two substituents arepresent, the substituents can be the same or different. In someembodiments, the aryl group of the aryl(C₁₋₆ alkyl) can be a para-,ortho- or meta-substituted phenyl.

In some embodiments, R^(6A) and R^(7A) can be both

In some embodiments, at least one of R^(6A) and R^(7A) can be

In some embodiments, R^(25A) can be hydrogen. In other embodiments,R^(25A) can be an optionally substituted C₁₋₂₄ alkyl. In still otherembodiments, R^(25A) can be an optionally substituted aryl. In someembodiments, R^(25A) can be a C₁₋₆ alkyl, for example, methyl, ethyl,n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl (branched andstraight-chained), and hexyl (branched and straight-chained).

In some embodiments, R^(6A) and R^(7A) can be both

In some embodiments, at least one of R^(6A) and R^(7A) can be

In some embodiments, R^(29A) can be hydrogen. In other embodiments,R^(29A) can be an optionally substituted C₁₋₂₄ alkyl. In someembodiments, R^(29A) can be a C₁₋₄ alkyl, such as methyl, ethyl,n-propyl, iso-propyl, n-butyl, iso-butyl and t-butyl. In still otherembodiments, R^(29A) can be an optionally substituted aryl, such as anoptionally substituted phenyl or an optionally substituted naphthyl.

In some embodiments, R^(1A) can be

R^(6A) can be

R^(7A) can be absent or hydrogen; R^(12A), R^(13A) and R^(14A) can beindependently absent or hydrogen; and m can be 0 or 1. In someembodiments, m can be 0, and R^(7A), R^(12A) and R^(13A) can beindependently absent or hydrogen. In other embodiments, m can be 1, andR^(7A), R^(12A), R^(13A) and R^(14A) can be independently absent orhydrogen. Those skilled in the art understand that when m is 0, R^(6A)can be diphosphate, when Z^(1A) is oxygen, or an alpha-thiodiphosphate,when Z^(1A) is sulfur. Likewise, those skilled in the art understandthat when m is 1, R^(6A) can be triphosphate, when Z^(1A) is oxygen, oran alpha-thiotriphosphate, when Z^(1A) is sulfur.

In some embodiments, R^(6A) and R^(7A) can be taken together to form anoptionally substituted

For example, R^(1A) can be an optionally substituted

When substituted, the ring can be substituted 1, 2, 3 or 3 or moretimes. When substituted with multiple substituents, the substituents canbe the same or different. In some embodiments, when R^(1A) is

the ring can be substituted with an optionally substituted aryl groupand/or an optionally substituted heteroaryl. An example of a suitableheteroaryl is pyridinyl. In some embodiments, R^(6A) and R^(7A) can betaken together to form an optionally substituted

such as

wherein R^(32A) can be an optionally substituted aryl, an optionallysubstituted heteroaryl or an optionally substituted heterocyclyl.

In some embodiments, R^(6A) and R^(7A) can be taken together to form anoptionally substituted

wherein the oxygens connected to R^(6A) and R^(7A), the phosphorus andthe moiety form a six-membered to ten-membered ring system. Example ofan optionally substituted

include

In some embodiments, R^(6A) and R^(7A) can be the same. In someembodiments, R^(6A) and R^(7A) can be the different.

In some embodiments, Z^(1A) can be oxygen. In other embodiments, Z^(1A)can be sulfur.

In some embodiments, R^(1A) can be

In some embodiments, R^(8A) can be selected from absent, hydrogen, anoptionally substituted C₁₋₂₄ alkyl, an optionally substituted C₂₋₂₄alkenyl, an optionally substituted C₂₋₂₄ alkynyl, an optionallysubstituted C₃₋₆ cycloalkyl and an optionally substituted C₃₋₆cycloalkenyl; and R^(9A) can be independently selected from anoptionally substituted C₁₋₂₄ alkyl, an optionally substituted C₂₋₂₄alkenyl, an optionally substituted C₂₋₂₄ alkynyl, an optionallysubstituted C₃₋₆ cycloalkyl and an optionally substituted C₃₋₆cycloalkenyl.

In some embodiments, R^(8A) can be hydrogen, and R^(9A) can be anoptionally substituted C₁₋₆ alkyl. Examples of suitable C₁₋₆ alkylsinclude methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl,tert-butyl, pentyl (branched and straight-chained), and hexyl (branchedand straight-chained). In other embodiments, R^(8A) can be hydrogen, andR^(9A) can be NR^(30A)R^(31A), wherein R³⁰ and R³¹ can be independentlyselected from hydrogen, an optionally substituted C₁₋₂₄ alkyl, anoptionally substituted C₂₋₂₄ alkenyl, an optionally substituted C₂₋₂₄alkynyl, an optionally substituted C₃₋₆ cycloalkyl and an optionallysubstituted C₃₋₆ cycloalkenyl.

In some embodiments, R^(8A) can be absent or hydrogen; and R^(9A) can bean optionally substituted N-linked amino acid or an optionallysubstituted N-linked amino acid ester derivative. In other embodiments,R^(8A) can be an optionally substituted aryl; and R^(9A) can be anoptionally substituted N-linked amino acid or an optionally substitutedN-linked amino acid ester derivative. In still other embodiments, R^(8A)can be an optionally substituted heteroaryl; and R^(9A) can be anoptionally substituted N-linked amino acid or an optionally substitutedN-linked amino acid ester derivative. In some embodiments, R^(9A) can beselected from alanine, asparagine, aspartate, cysteine, glutamate,glutamine, glycine, proline, serine, tyrosine, arginine, histidine,isoleucine, leucine, lysine, methionine, phenylalanine, threonine,tryptophan, valine and ester derivatives thereof. Examples of anoptionally substituted N-linked amino acid ester derivatives includeoptionally substituted versions of the following: alanine isopropylester, alanine cyclohexyl ester, alanine neopentyl ester, valineisopropyl ester and leucine isopropyl ester. In some embodiments, R^(9A)can have the structure

wherein R^(33A) can be selected from hydrogen, an optionally substitutedC₁₋₆-alkyl, an optionally substituted C₃₋₆ cycloalkyl, an optionallysubstituted aryl, an optionally substituted aryl(C₁₋₆ alkyl) and anoptionally substituted haloalkyl; R^(34A) can be selected from hydrogen,an optionally substituted C₁₋₆ alkyl, an optionally substituted C₁₋₆haloalkyl, an optionally substituted C₃₋₆ cycloalkyl, an optionallysubstituted C₆ aryl, an optionally substituted C₁₀ aryl and anoptionally substituted aryl(C₁₋₆ alkyl); and R^(35A) can be hydrogen oran optionally substituted C₁₋₄-alkyl; or R^(34A) and R^(35A) can betaken together to form an optionally substituted C₃₋₆ cycloalkyl.

When R^(34A) is substituted, R^(34A) can be substituted with one or moresubstituents selected from N-amido, mercapto, alkylthio, an optionallysubstituted aryl, hydroxy, an optionally substituted heteroaryl,O-carboxy, and amino. In some embodiments, R^(34A) can be anunsubstituted C₁₋₆-alkyl, such as those described herein. In someembodiments, R^(34A) can be hydrogen. In other embodiments, R^(34A) canbe methyl. In some embodiments, R^(33A) can be an optionally substitutedC₁₋₆ alkyl. Examples of optionally substituted C₁₋₆-alkyls includeoptionally substituted variants of the following: methyl, ethyl,n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl (branched andstraight-chained), and hexyl (branched and straight-chained). In someembodiments, R^(33A) can be methyl or isopropyl. In some embodiments,R^(33A) can be ethyl or neopentyl. In other embodiments, R^(33A) can bean optionally substituted C₃₋₆ cycloalkyl. Examples of optionallysubstituted C₃₋₆ cycloalkyl include optionally substituted variants ofthe following: cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl. Inan embodiment, R^(33A) can be an optionally substituted cyclohexyl. Instill other embodiments, R^(33A) can be an optionally substituted aryl,such as phenyl and naphthyl. In yet still other embodiments, R^(33A) canbe an optionally substituted aryl(C₁₋₆ alkyl). In some embodiments,R^(33A) can be an optionally substituted benzyl. In some embodiments,R^(33A) can be an optionally substituted C₁₋₆ haloalkyl, for example,CF₃. In some embodiments, R^(35A) can be hydrogen. In other embodiments,R^(35A) can be an optionally substituted C₁₋₄-alkyl, such as methyl,ethyl, n-propyl, isopropyl, n-butyl, isobutyl and tert-butyl. In anembodiment, R^(35A) can be methyl. In some embodiments, R^(34A) andR^(35A) can be taken together to form an optionally substituted C₃₋₆cycloalkyl. Examples of optionally substituted C₃₋₆ cycloalkyl includeoptionally substituted variants of the following: cyclopropyl,cyclobutyl, cyclopentyl, and cyclohexyl. Depending on the groups thatare selected for R^(34A) and R^(35A), the carbon to which R^(34A) andR^(35A) are attached may be a chiral center. In some embodiment, thecarbon to which R^(34A) and R^(35A) are attached may be a (R)-chiralcenter. In other embodiments, the carbon to which R^(34A) and R^(35A)are attached may be a (S)-chiral center.

In some embodiments, when R^(1A) is

Z^(2A) can be O (oxygen). In other embodiments, when R^(1A) is

Z^(2A) can be S (sulfur).

In some embodiments, R^(1A) can be

In some embodiments, R^(10A) and R^(11A) can be both an optionallysubstituted N-linked amino acid or an optionally substituted N-linkedamino acid ester derivative. In some embodiments, R^(10A) and R^(11A)can be independently selected from alanine, asparagine, aspartate,cysteine, glutamate, glutamine, glycine, proline, serine, tyrosine,arginine, histidine, isoleucine, leucine, lysine, methionine,phenylalanine, threonine, tryptophan, valine and ester derivativesthereof. In some embodiments, R^(10A) and R^(11A) can be an optionallysubstituted version of the following: alanine isopropyl ester, alaninecyclohexyl ester, alanine neopentyl ester, valine isopropyl ester andleucine isopropyl ester. In some embodiments, R^(10A) and R^(11A) canindependently have the structure

wherein R^(36A) can be selected from hydrogen, an optionally substitutedC₁₋₆-alkyl, an optionally substituted C₃₋₆ cycloalkyl, an optionallysubstituted aryl, an optionally substituted aryl(C₁₋₆ alkyl) and anoptionally substituted haloalkyl; R^(37A) can be selected from hydrogen,an optionally substituted C₁₋₆ alkyl, an optionally substituted C₁₋₆haloalkyl, an optionally substituted C₃₋₆ cycloalkyl, an optionallysubstituted C₆ aryl, an optionally substituted C₁₀ aryl and anoptionally substituted aryl(C₁₋₆ alkyl); and R^(38A) can be hydrogen oran optionally substituted C₁₋₄-alkyl; or R^(37A) and R^(38A) can betaken together to form an optionally substituted C₃₋₆ cycloalkyl.

When R^(37A) is substituted, R^(37A) can be substituted with one or moresubstituents selected from N-amido, mercapto, alkylthio, an optionallysubstituted aryl, hydroxy, an optionally substituted heteroaryl,O-carboxy, and amino. In some embodiments, R^(37A) can be anunsubstituted C₁₋₆-alkyl, such as those described herein. In someembodiments, R^(37A) can be hydrogen. In other embodiments, R^(37A) canbe methyl. In some embodiments, R^(36A) can be an optionally substitutedC₁₋₆ alkyl. Examples of optionally substituted C₁₋₆-alkyls includeoptionally substituted variants of the following: methyl, ethyl,n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl (branched andstraight-chained), and hexyl (branched and straight-chained). In someembodiments, R^(36A) can be methyl or isopropyl. In some embodiments,R^(36A) can be ethyl or neopentyl. In other embodiments, R^(36A) can bean optionally substituted C₃₋₆ cycloalkyl. Examples of optionallysubstituted C₃₋₆ cycloalkyl include optionally substituted variants ofthe following: cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl. Inan embodiment, R^(36A) can be an optionally substituted cyclohexyl. Instill other embodiments, R^(36A) can be an optionally substituted aryl,such as phenyl and naphthyl. In yet still other embodiments, R^(36A) canbe an optionally substituted aryl(C₁₋₆ alkyl). In some embodiments,R^(36A) can be an optionally substituted benzyl. In some embodiments,R^(36A) can be an optionally substituted C₁₋₆ haloalkyl, for example,CF₃. In some embodiments, R^(38A) can be hydrogen. In other embodiments,R^(38A) can be an optionally substituted C₁₋₄-alkyl, such as methyl,ethyl, n-propyl, isopropyl, n-butyl, isobutyl and tert-butyl. In anembodiment, R^(38A) can be methyl. In some embodiments, R^(37A) andR^(38A) can be taken together to form an optionally substituted C₃₋₆cycloalkyl. Examples of optionally substituted C₃₋₆ cycloalkyl includeoptionally substituted variants of the following: cyclopropyl,cyclobutyl, cyclopentyl, and cyclohexyl. Depending on the groups thatare selected for R^(37A) and R^(38A), the carbon to which R^(37A) andR^(38A) are attached may be a chiral center. In some embodiment, thecarbon to which R^(37A) and R^(38A) are attached may be a (R)-chiralcenter. In other embodiments, the carbon to which R^(37A) and R^(38A)are attached may be a (S)-chiral center.

Examples of suitable

groups include the following:

In some embodiments, R^(10A) and R^(11A) can be the same. In someembodiments, R^(10A) and R^(11A) can be the different.

In some embodiments, Z^(3A) can be O (oxygen). In other embodiments,Z^(3A) can be S (sulfur).

In some embodiments, R^(1A) can be hydrogen. In some embodiments, R^(1A)can be an optionally substituted acyl. In other embodiments, R^(1A) canbe —C(═O)R^(39A), wherein R^(39A) can be selected from an optionallysubstituted C₁₋₁₂ alkyl, an optionally substituted C₂₋₁₂ alkenyl, anoptionally substituted C₂₋₁₂ alkynyl, an optionally substituted C₃₋₈cycloalkyl, an optionally substituted C₅₋₈ cycloalkenyl, an optionallysubstituted C₆₋₁₀ aryl, an optionally substituted heteroaryl, anoptionally substituted heterocyclyl, an optionally substituted aryl(C₁₋₆alkyl), an optionally substituted heteroaryl(C₁₋₆ alkyl) and anoptionally substituted heterocyclyl(C₁₋₆ alkyl). In some embodiments,R^(39A) can be a substituted C₁₋₁₂ alkyl. In other embodiments, R^(39A)can be an unsubstituted C₁₋₁₂ alkyl.

In still other embodiments, R^(1A) can be an optionally substitutedO-linked amino acid. Examples of suitable O-linked amino acids includealanine, asparagine, aspartate, cysteine, glutamate, glutamine, glycine,proline, serine, tyrosine, arginine, histidine, isoleucine, leucine,lysine, methionine, phenylalanine, threonine, tryptophan and valine.Additional examples of suitable amino acids include, but are not limitedto, ornithine, hypusine, 2-aminoisobutyric acid, dehydroalanine,gamma-aminobutyric acid, citrulline, beta-alanine, alpha-ethyl-glycine,alpha-propyl-glycine and norleucine. In some embodiments, the O-linkedamino acid can have the structure

wherein R^(40A) can be selected from hydrogen, an optionally substitutedC₁₋₆ alkyl, an optionally substituted C₁₋₆ haloalkyl, an optionallysubstituted C₃₋₆ cycloalkyl, an optionally substituted C₆ aryl, anoptionally substituted C₁₀ aryl and an optionally substituted aryl(C₁₋₆alkyl); and R^(41A) can be hydrogen or an optionally substitutedC₁₋₄-alkyl; or R^(40A) and R^(41A) can be taken together to form anoptionally substituted C₃₋₆ cycloalkyl. Those skilled in the artunderstand that when R^(1A) is an optionally substituted O-linked aminoacid, the oxygen of R^(1A)O— of Formula (I) is part of the optionallysubstituted O-linked amino acid. For example, when R^(1A) is

the oxygen indicated with “*” is the oxygen of R^(1A)O— of Formula (I).

When R^(40A) is substituted, R^(40A) can be substituted with one or moresubstituents selected from N-amido, mercapto, alkylthio, an optionallysubstituted aryl, hydroxy, an optionally substituted heteroaryl,O-carboxy, and amino. In some embodiments, R^(40A) can be anunsubstituted C₁₋₆-alkyl, such as those described herein. In someembodiments, R^(40A) can be hydrogen. In other embodiments, R^(40A) canbe methyl. In some embodiments, R^(41A) can be hydrogen. In otherembodiments, R^(41A) can be an optionally substituted C₁₋₄-alkyl, suchas methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl and tert-butyl.In an embodiment, R^(41A) can be methyl. Depending on the groups thatare selected for R^(40A) and R^(41A), the carbon to which R^(40A) andR^(41A) are attached may be a chiral center. In some embodiment, thecarbon to which R^(40A) and R^(41A) are attached may be a (R)-chiralcenter. In other embodiments, the carbon to which R^(40A) and R^(41A)are attached may be a (S)-chiral center.

Examples of suitable

include the following:

In some embodiments, the dashed line (------) can be a single bond,R^(2A) can be CH₂, and R^(3A) can be O (oxygen). When the dashed line(------) is a single bond, R^(2A) is CH₂, and R^(3A) is O (oxygen), a4-membered ring is formed that includes the 4′-carbon and 3′-carbon ofthe pentose ring. In other embodiments, the dashed line (------) can beabsent, R^(2A) can be selected from an optionally substituted C₁₋₆alkyl, an optionally substituted C₂₋₆ alkenyl, an optionally substitutedC₂₋₆ alkynyl, an optionally substituted —O—C₁₋₆ alkyl, an optionallysubstituted —O—C₃₋₆ alkenyl, an optionally substituted —O—C₃₋₆ alkynyland cyano, and R^(3A) can be selected from OH, —OC(═O)R″^(A) and anoptionally substituted O-linked amino acid.

Various groups can be attached to the 4′-position of the pentose ring.In some embodiments, R^(2A) can be an optionally substituted C₁₋₆ alkyl.Examples of suitable C₁₋₆ alkyls include methyl, ethyl, n-propyl,isopropyl, n-butyl, isobutyl, tert-butyl, pentyl (branched andstraight-chained), and hexyl (branched and straight-chained). In someembodiments, R^(2A) can be an unsubstituted C₁₋₆ alkyl. In otherembodiments, R^(2A) can be a substituted C₁₋₆ alkyl. For example, R^(2A)can be a halogen substituted C₁₋₆ alkyl, a hydroxy substituted C₁₋₆alkyl, an alkoxy substituted C₁₋₆ alkyl or a sulfenyl substituted C₁₋₆alkyl (for example, —C₁₋₆ alkyl-S—C₁₋₆ alkyl). In other embodiments,R^(2A) can be a C₁₋₆ haloalkyl. In other embodiments, R^(2A) can be anoptionally substituted C₂₋₆ alkenyl. In some embodiments, R^(2A) can bea substituted C₂₋₆ alkenyl. In other embodiments, R^(2A) can be anunsubstituted C₂₋₆ alkenyl. For example, R^(2A) can be ethenyl, propenylor allenyl. In still other embodiments, R^(2A) can be an optionallysubstituted C₂₋₆ alkynyl. In some embodiments, R^(2A) can be asubstituted C₂₋₆ alkynyl. In other embodiments, R^(2A) can be anunsubstituted C₂₋₆ alkynyl. Suitable C₂₋₆ alkynyls include ethynyl andpropynyl. In yet still other embodiments, R^(2A) can be an optionallysubstituted C₃₋₆ cycloalkyl. In some embodiments, R^(2A) can be asubstituted C₃₋₆ cycloalkyl. In other embodiments, R^(2A) can be anunsubstituted C₃₋₆ cycloalkyl. A non-limiting list of C₃₋₆ cycloalkylsinclude cyclopropyl, cyclobutyl, cyclopentyl and cyclohexyl. In someembodiments, R^(2A) can be an optionally substituted —O—C₁₋₆ alkyl. Insome embodiments, R^(2A) can be a substituted —O—C₁₋₆ alkyl. In otherembodiments, R^(2A) can be an unsubstituted —O—C₁₋₆ alkyl. Examples ofsuitable O—C₁₋₆ alkyl groups include methoxy, ethoxy, n-propoxy,iso-propoxy, n-butoxy, isobutoxy, tert-butoxy, pentoxy (branched andstraight-chained), and hexoxy (branched and straight-chained). In otherembodiments, R^(2A) can be an optionally substituted —O—C₃₋₆ alkenyl. Insome embodiments, R^(2A) can be a substituted —O—C₃₋₆ alkenyl. In otherembodiments, R^(2A) can be an unsubstituted —O—C₃₋₆ alkenyl. In stillother embodiments, R^(2A) can be an optionally substituted —O—C₃₋₆alkynyl. In some embodiments, R^(2A) can be a substituted —O—C₃₋₆alkynyl. In other embodiments, R^(2A) can be an unsubstituted —O—C₃₋₆alkynyl. In yet still other embodiments, R^(2A) can be cyano.

The groups attached to the 3′-position of the pentose ring can vary. Insome embodiments, including those of paragraph [0120], R^(3A) can be OH.In other embodiments, including those of paragraph [0120], R^(3A) can bean optionally substituted O-linked amino acid. Examples of suitableO-linked amino acids include alanine, asparagine, aspartate, cysteine,glutamate, glutamine, glycine, proline, serine, tyrosine, arginine,histidine, isoleucine, leucine, lysine, methionine, phenylalanine,threonine, tryptophan and valine. Additional examples of suitable aminoacids include, but are not limited to, ornithine, hypusine,2-aminoisobutyric acid, dehydroalanine, gamma-aminobutyric acid,citrulline, beta-alanine, alpha-ethyl-glycine, alpha-propyl-glycine andnorleucine. In some embodiments, the O-linked amino acid can have thestructure

wherein R^(42A) can be selected from hydrogen, an optionally substitutedC₁₋₆ alkyl, an optionally substituted C₁₋₆ haloalkyl, an optionallysubstituted C₃₋₆ cycloalkyl, an optionally substituted C₆ aryl, anoptionally substituted C₁₀ aryl and an optionally substituted aryl(C₁₋₆alkyl); and R^(43A) can be hydrogen or an optionally substitutedC₁₋₄-alkyl; or R^(42A) and R^(43A) can be taken together to form anoptionally substituted C₃₋₆ cycloalkyl.

When R^(42A) is substituted, R^(42A) can be substituted with one or moresubstituents selected from N-amido, mercapto, alkylthio, an optionallysubstituted aryl, hydroxy, an optionally substituted heteroaryl,O-carboxy, and amino. In some embodiments, R^(42A) can be anunsubstituted C₁₋₆-alkyl, such as those described herein. In someembodiments, R^(42A) can be hydrogen. In other embodiments, R^(42A) canbe methyl. In some embodiments, R^(43A) can be hydrogen. In otherembodiments, R^(43A) can be an optionally substituted C₁₋₄-alkyl, suchas methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl and tert-butyl.In an embodiment, R^(43A) can be methyl. Depending on the groups thatare selected for R^(42A) and R^(43A), the carbon to which R^(42A) andR^(43A) are attached may be a chiral center. In some embodiment, thecarbon to which R^(42A) and R^(43A) are attached may be a (R)-chiralcenter. In other embodiments, the carbon to which R^(42A) and R^(43A)are attached may be a (S)-chiral center.

Examples of suitable

include the following:

In still other embodiments, including those of paragraph [0120], R^(3A)can be —OC(═O)R″^(A), wherein R″^(A) can be an optionally substitutedC₁₋₂₄ alkyl. In some embodiments, R″^(A) can be a substituted C₁₋₈alkyl. In other embodiments, R″^(A) can be an unsubstituted C₁₋₈ alkyl.In still other embodiments, including those of paragraph [0120], R^(3A)can be an optionally substituted —O-acyl. In yet still otherembodiments, including those of paragraph [0120], R^(3A) can be—OC(═O)R^(44A), wherein R^(44A) can be selected from an optionallysubstituted C₁₋₁₂ alkyl, an optionally substituted C₂₋₁₂ alkenyl, anoptionally substituted C₂₋₁₂ alkynyl, an optionally substituted C₃₋₈cycloalkyl, an optionally substituted C₅₋₈ cycloalkenyl, an optionallysubstituted C₆₋₁₀ aryl, an optionally substituted heteroaryl, anoptionally substituted heterocyclyl, an optionally substituted aryl(C₁₋₆alkyl), an optionally substituted heteroaryl(C₁₋₆ alkyl) and anoptionally substituted heterocyclyl(C₁₋₆ alkyl). In some embodiments,R^(44A) can be a substituted C₁₋₁₂ alkyl. In other embodiments, R^(44A)can be an unsubstituted C₁₋₁₂ alkyl.

Various substituents can be present at the 2′-position of the pentosering. In some embodiments, R^(5A) can be hydrogen. In other embodiments,R^(5A) can be halogen, for example, fluoro. In some embodiments, R^(4A)can be halogen, such as fluoro. In some embodiments, R^(5A) can behydrogen and R^(4A) can be halogen. In other embodiments, R^(4A) andR^(5A) can both be halogen.

In some embodiments, ---- can be a single bond, R^(4A) can be fluoro,R^(5A) can be hydrogen and R^(2A) can be a C₁₋₆ haloalkyl. In someembodiments, ---- can be a single bond, R^(4A) can be fluoro, R^(5A) canbe hydrogen, R^(2A) can be a C₁₋₆ haloalkyl and B^(1A) can be cytosine.

In some embodiments, R^(2A) cannot be methoxy. In some embodiments,R^(2A) cannot be methoxy when B^(1A) is substituted or unsubstituteduracil. In some embodiments, B^(1A) is substituted or unsubstitutedcytosine. In other embodiments, B^(1A) is substituted or unsubstitutedthymine. In still other embodiments, B^(1A) cannot be an unsubstituteduracil. In some embodiments, R^(2A) cannot be methoxy when Z^(1A) is

wherein R^(8A) is an unsubstituted C₁₋₆ alkyl or a para-substitutedphenyl; and R^(9A) is an optionally substituted N-linked amino acid oran optionally substituted N-linked amino acid ester derivative. In someembodiments, R^(2A) cannot be methoxy when Z^(1A) is

In some embodiments, R^(2A) cannot be an alkoxy (for example, whenZ^(1A) is

In some embodiments, B^(1A) cannot be cytosine when R^(2A) is anunsubstituted alkenyl or an unsubstituted alkynyl. In some embodiments,B^(1A) cannot be thymine when R^(2A) is an optionally substituted alkyl.In some embodiments, R^(2A) cannot be an unsubstituted alkoxy (such asmethoxy), an optionally substituted alkenyl (such as allenyl), anunsubstituted alkynyl (such as ethynyl) or a C₁ alkyl substituted with anon-halogen substituent. In some embodiments, R^(2A) cannot be anunsubstituted alkoxy (such as methoxy), an optionally substitutedalkenyl (such as allenyl), an optionallys substituted substitutedalkynyl (such as ethynyl) or a C₁₋₄ alkyl substituted with a non-halogensubstituent. In some embodiments R^(1A) cannot be H. In some embodimentsR^(1A) cannot be H when B^(1A) is an optionally substituted cytosine oran optionally substituted thymine.

Various optionally substituted heterocyclic bases can be attached to thepentose ring. In some embodiments, one or more of the amine and/or aminogroups may be protected with a suitable protecting group. For example,an amino group may be protected by transforming the amine and/or aminogroup to an amide or a carbamate. In some embodiments, an optionallysubstituted heterocyclic base or an optionally substituted heterocyclicbase with one or more protected amino groups can have one of thefollowing structures:

wherein: R^(A2) can be selected from hydrogen, halogen and NHR^(J2),wherein R^(J2) can be selected from hydrogen, —C(═O)R^(K2) and—C(═O)OR^(L2); R^(B2) can be halogen or NHR^(W2), wherein R^(W2) can beselected from hydrogen, an optionally substituted C₁₋₆ alkyl, anoptionally substituted C₂₋₆ alkenyl, an optionally substituted C₃₋₈cycloalkyl, —C(═O)R^(M2) and —C(═O)OR^(N2); R^(C2) can be hydrogen orNHR^(O2), wherein R^(O2) can be selected from hydrogen, —C(═O)R^(P2) and—C(═O)OR^(Q2); R^(D2) can be selected from hydrogen, halogen, anoptionally substituted C₁₋₆ alkyl, an optionally substituted C₂₋₆alkenyl and an optionally substituted C₂₋₆ alkynyl; R^(E2) can beselected from hydrogen, hydroxy, an optionally substituted C₁₋₆ alkyl,an optionally substituted C₃₋₈ cycloalkyl, —C(═O)R^(R2) and—C(═O)OR^(S2); R^(F2) can be selected from hydrogen, halogen, anoptionally substituted C₁₋₆ alkyl, an optionally substituted C₂₋₆alkenyl and an optionally substituted C₂₋₆ alkynyl; Y² and Y³ can beindependently N (nitrogen) or CR^(I2), wherein R^(I2) can be selectedfrom hydrogen, halogen, an optionally substituted C₁₋₆-alkyl, anoptionally substituted C₂₋₆-alkenyl and an optionally substitutedC₂₋₆-alkynyl; R^(G2) can be an optionally substituted C₁₋₆ alkyl; R^(H2)can be hydrogen or NHR^(T2), wherein R^(T2) can be independentlyselected from hydrogen, —C(═O)R^(U2) and —C(═O)OR^(v2); and R^(K2),R^(L2), R^(M2), R^(N2), R^(P2), R^(Q2), R^(R2), R^(S2), R^(U2) andR^(V2) can be independently selected from C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆alkynyl, C₃₋₆ cycloalkyl, C₃₋₆ cycloalkenyl, C₆₋₁₀ aryl, heteroaryl,heteroalicyclyl, aryl(C₁₋₆ alkyl), heteroaryl(C₁₋₆ alkyl) andheteroalicyclyl(C₁₋₆ alkyl). In some embodiments, the structures shownabove can be modified by replacing one or more hydrogens withsubstituents selected from the list of substituents provided for thedefinition of “substituted.”

In some embodiments, B^(1A) can be

In other embodiments, B^(1A) can be

In still other embodiments, B^(1A) can be

such as

In yet still other embodiments, B^(1A) can be

for example,

In some embodiments, R^(D2) can be hydrogen. In other embodiments,B^(1A) can be

In some embodiments, R^(B2) can be NH₂. In other embodiments, R^(B2) canbe NHR^(W2), wherein R^(W2) can be —C(═O)R^(M2) or —C(═O)OR^(N2). Instill other embodiments, B^(1A) can be

In some embodiments, B^(1A) can be

In some embodiments, a compound of Formula (I) can have a structureselected from one of the following:

or a pharmaceutically acceptable salt of the foregoing. In someembodiments of this paragraph, B^(1A) can be an optionally substitutedpurine base. In other embodiments of this paragraph, B^(1A) can be anoptionally substituted pyrimidine base. In some embodiments of thisparagraph, B^(1A) can be guanine. In other embodiments of thisparagraph, B^(1A) can be thymine. In still other embodiments of thisparagraph, B^(1A) can be cytosine. In yet still other embodiments ofthis paragraph, B^(1A) can be uracil. In some embodiments of thisparagraph, B^(1A) can be adenine. In some embodiments of this paragraph,R^(1A) can be hydrogen. In other embodiments of this paragraph, R^(1A)can be an optionally substituted acyl. In still other embodiments ofthis paragraph, R^(1A) can be mono-, di- or tri-phosphate. In yet otherembodiments of this paragraph, R^(1A) can be phosphoroamidate. In someembodiments of this paragraph, R^(1A) can be an acyloxyalkyl esterphosphate prodrug.

In some embodiments, the compound can be a compound of Formula (II), ora pharmaceutically acceptable salt thereof, wherein: B^(1B) can be anoptionally substituted heterocyclic base or an optionally substitutedheterocyclic base with a protected amino group; R^(1B) can be selectedfrom O⁻, OH,

an optionally substituted N-linked amino acid and an optionallysubstituted N-linked amino acid ester derivative; R^(2B) can be selectedfrom an optionally substituted C₁₋₆ alkyl, an optionally substitutedC₂₋₆ alkenyl, an optionally substituted C₂₋₆ alkynyl, an optionallysubstituted —O—C₁₋₆ alkyl, an optionally substituted —O—C₃₋₆ alkenyl, anoptionally substituted —O—C₃₋₆ alkynyl and cyano; R^(3B) can be ahalogen; R^(4B) can be hydrogen or halogen; R^(5B), R^(6B), R^(8B) andR^(9B) can be independently selected from hydrogen, an optionallysubstituted C₁₋₂₄ alkyl and an optionally substituted aryl; R^(7B) andR^(10B) can be independently selected from hydrogen, an optionallysubstituted C₁₋₂₄ alkyl, an optionally substituted aryl, an optionallysubstituted —O—C₁₋₂₄ alkyl and an optionally substituted —O-aryl;R^(11B) can be selected from hydrogen, an optionally substituted C₁₋₂₄alkyl and an optionally substituted aryl; Z^(1B) and Z^(2B) can beindependently O or S.

In some embodiments, R^(1B) can be O⁻. In other embodiments, R^(1B) canbe OH.

In some embodiments, R^(1B) can be

wherein R^(5B) and R^(6B) can be independently selected from hydrogen,an optionally substituted C₁₋₂₄ alkyl and an optionally substitutedaryl; and R^(7B) can be selected from hydrogen, an optionallysubstituted C₁₋₂₄ alkyl, an optionally substituted aryl, an optionallysubstituted —O—C₁₋₂₄ alkyl and an optionally substituted —O-aryl. Insome embodiments, R^(5B) and R^(6B) can be hydrogen. In otherembodiments, at least one of R^(5B) and R^(6B) can be an optionallysubstituted C₁₋₂₄ alkyl or an optionally substituted aryl. In someembodiments, R^(7B) can be an optionally substituted C₁₋₂₄ alkyl. Inother embodiments, R^(7B) can be an optionally substituted aryl. Instill other embodiments, R^(7B) can be an optionally substituted—O—C₁₋₂₄ alkyl or an optionally substituted —O-aryl.

In some embodiments, R^(1B) can be

wherein R^(8B) and R^(9B) can be independently selected from hydrogen,an optionally substituted C₁₋₂₄ alkyl and an optionally substitutedaryl; R^(10B) can be independently selected from hydrogen, an optionallysubstituted C₁₋₂₄ alkyl, an optionally substituted aryl, an optionallysubstituted —O—C₁₋₂₄ alkyl and an optionally substituted —O-aryl; andZ^(2B) can be independently O (oxygen) or S (sulfur). In someembodiments, R^(8B) and R^(9B) can be hydrogen. In other embodiments, atleast one of R^(8B) and R^(9B) can be an optionally substituted C₁₋₂₄alkyl or an optionally substituted aryl. In some embodiments, R^(10B)can be an optionally substituted C₁₋₂₄ alkyl. In other embodiments,R^(10B) can be an optionally substituted aryl. In still otherembodiments, R^(10B) can be an optionally substituted —O—C₁₋₂₄ alkyl oran optionally substituted —O-aryl. In some embodiments, Z^(2B) can be O(oxygen). In other embodiments, Z^(2B) can be or S (sulfur). In someembodiments, R^(1B) can be isopropylcarbonyloxymethyloxy. In someembodiments, R^(1B) can be pivaloyloxymethyloxy.

In some embodiments, R^(1B) can be

In some embodiments, R^(11B) can be hydrogen. In other embodiments,R^(11B) can be an optionally substituted C₁₋₂₄ alkyl. In still otherembodiments, R^(11B) can be an optionally substituted aryl. In someembodiments, R^(11B) can be a C₁₋₆ alkyl, for example, methyl, ethyl,n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl (branched andstraight-chained), and hexyl (branched and straight-chained).

In some embodiments, R^(1B) can be an optionally substituted N-linkedamino acid or an optionally substituted N-linked amino acid esterderivative. For example, R^(1B) can be optionally substituted version ofthe following: alanine, asparagine, aspartate, cysteine, glutamate,glutamine, glycine, proline, serine, tyrosine, arginine, histidine,isoleucine, leucine, lysine, methionine, phenylalanine, threonine,tryptophan, valine and ester derivatives thereof. In some embodiments,R^(1B) can be selected from alanine isopropyl ester, alanine cyclohexylester, alanine neopentyl ester, valine isopropyl ester and leucineisopropyl ester. In some embodiments, R^(1B) can have the structure

wherein R^(12B) can be selected from hydrogen, an optionally substitutedC₁₋₆-alkyl, an optionally substituted C₃₋₆ cycloalkyl, an optionallysubstituted aryl, an optionally substituted aryl(C₁₋₆ alkyl) and anoptionally substituted haloalkyl; R^(13B) can be selected from hydrogen,an optionally substituted C₁₋₆ alkyl, an optionally substituted C₁₋₆haloalkyl, an optionally substituted C₃₋₆ cycloalkyl, an optionallysubstituted C₆ aryl, an optionally substituted C₁₀ aryl and anoptionally substituted aryl(C₁₋₆ alkyl); and R^(14B) can be hydrogen oran optionally substituted C₁₋₄-alkyl; or R^(13B) and R^(14B) can betaken together to form an optionally substituted C₃₋₆ cycloalkyl.

When R^(13B) is substituted, R^(13B) can be substituted with one or moresubstituents selected from N-amido, mercapto, alkylthio, an optionallysubstituted aryl, hydroxy, an optionally substituted heteroaryl,O-carboxy, and amino. In some embodiments, R^(13B) can be anunsubstituted C₁₋₆-alkyl, such as those described herein. In someembodiments, R^(13B) can be hydrogen. In other embodiments, R^(13B) canbe methyl. In some embodiments, R^(12B) can be an optionally substitutedC₁₋₆ alkyl. Examples of optionally substituted C₁₋₆-alkyls includeoptionally substituted variants of the following: methyl, ethyl,n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl (branched andstraight-chained), and hexyl (branched and straight-chained). In someembodiments, R^(12B) can be methyl or isopropyl. In some embodiments,R^(12B) can be ethyl or neopentyl. In other embodiments, R^(12B) can bean optionally substituted C₃₋₆ cycloalkyl. Examples of optionallysubstituted C₃₋₆ cycloalkyl include optionally substituted variants ofthe following: cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl. Inan embodiment, R^(12B) can be an optionally substituted cyclohexyl. Instill other embodiments, R^(12B) can be an optionally substituted aryl,such as phenyl and naphthyl. In yet still other embodiments, R^(12B) canbe an optionally substituted aryl(C₁₋₆ alkyl). In some embodiments,R^(12B) can be an optionally substituted benzyl. In some embodiments,R^(12B) can be an optionally substituted C₁₋₆ haloalkyl, for example,CF₃. In some embodiments, R^(14B) can be hydrogen. In other embodiments,R^(14B) can be an optionally substituted C₁₋₄-alkyl, such as methyl,ethyl, n-propyl, isopropyl, n-butyl, isobutyl and tert-butyl. In anembodiment, R^(14B) can be methyl. In some embodiments, R^(13B) andR^(14B) can be taken together to form an optionally substituted C₃₋₆cycloalkyl. Examples of optionally substituted C₃₋₆ cycloalkyl includeoptionally substituted variants of the following: cyclopropyl,cyclobutyl, cyclopentyl, and cyclohexyl. Depending on the groups thatare selected for R^(13B) and R^(14B), the carbon to which R^(13B) andR^(14B) are attached may be a chiral center. In some embodiment, thecarbon to which R^(13B) and R^(14B) are attached may be a (R)-chiralcenter. In other embodiments, the carbon to which R^(13B) and R^(14B)are attached may be a (S)-chiral center.

Examples of suitable

groups include the following:

A variety of substituents can be present at the 4′-position of thepentose ring. In some embodiments, R^(2B) can be an optionallysubstituted C₁₋₆ alkyl. Examples of suitable C₁₋₆ alkyls include methyl,ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl(branched and straight-chained), and hexyl (branched andstraight-chained). In some embodiments, R^(2B) can be an unsubstitutedC₁₋₆ alkyl. In other embodiments, R^(2B) can be a substituted C₁₋₆alkyl. For example, R^(2B) can be a halogen substituted C₁₋₆ alkyl, ahydroxy substituted C₁₋₆ alkyl, an alkoxy substituted C₁₋₆ alkyl or asulfenyl substituted C₁₋₆ alkyl (for example, —C₁₋₆ alkyl-S—C₁₋₆ alkyl).In other embodiments, R^(2B) can be a C₁₋₆ haloalkyl. In otherembodiments, R^(2B) can be an optionally substituted C₂₋₆ alkenyl. Insome embodiments, R^(2B) can be a substituted C₂₋₆ alkenyl. In otherembodiments, R^(2B) can be an unsubstituted C₂₋₆ alkenyl. For example,R^(2B) can be ethenyl, propenyl or allenyl. In still other embodiments,R^(2B) can be an optionally substituted C₂₋₆ alkynyl. In someembodiments, R^(2B) can be a substituted C₂₋₆ alkynyl. In otherembodiments, R^(2B) can be an unsubstituted C₂₋₆ alkynyl. Suitable C₂₋₆alkynyls include ethynyl and propynyl. In yet still other embodiments,R^(2B) can be an optionally substituted C₃₋₆ cycloalkyl. In someembodiments, R^(2B) can be a substituted C₃₋₆ cycloalkyl. In otherembodiments, R^(2B) can be an unsubstituted C₃₋₆ cycloalkyl. Anon-limiting list of C₃₋₆ cycloalkyls include cyclopropyl, cyclobutyl,cyclopentyl and cyclohexyl. In some embodiments, R^(2B) can be anoptionally substituted —O—C₁₋₆ alkyl. In some embodiments, R^(2B) can bea substituted —O—C₁₋₆ alkyl. In other embodiments, R^(2B) can be anunsubstituted —O—C₁₋₆ alkyl. Examples of suitable O—C₁₋₆ alkyl groupsinclude methoxy, ethoxy, n-propoxy, iso-propoxy, n-butoxy, isobutoxy,tert-butoxy, pentoxy (branched and straight-chained), and hexoxy(branched and straight-chained). In other embodiments, R^(2B) can be anoptionally substituted —O—C₃₋₆ alkenyl. In some embodiments, R^(2B) canbe a substituted —O—C₃₋₆ alkenyl. In other embodiments, R^(2B) can be anunsubstituted —O—C₃₋₆ alkenyl. In still other embodiments, R^(2B) can bean optionally substituted —O—C₃₋₆ alkynyl. In some embodiments, R^(2B)can be a substituted —O—C₃₋₆ alkynyl. In other embodiments, R^(2B) canbe an unsubstituted —O—C₃₋₆ alkynyl. In yet still other embodiments,R^(2B) can be cyano.

Variety of substituents can be present at the 2′-position of the pentosering. In some embodiments, R^(4B) can be hydrogen. In other embodiments,R^(4B) can be halogen, such as fluoro. In some embodiments, R^(3B) canbe halogen, such as fluoro. In some embodiments, R^(4B) can be hydrogenand R^(3B) can be halogen. In other embodiments, R^(3B) and R^(4B) canbe both halogen. For example, R^(3B) and R^(4B) can be both fluoro.

In some embodiments, Z^(1B) can be O (oxygen). In other embodiments,Z^(1B) can be S (sulfur).

Various optionally substituted heterocyclic bases can be attached to thepentose ring. In some embodiments, one or more of the amine and/or aminogroups may be protected with a suitable protecting group. For example,an amino group may be protected by transforming the amine and/or aminogroup to an amide or a carbamate. In some embodiments, an optionallysubstituted heterocyclic base or an optionally substituted heterocyclicbase with one or more protected amino groups can have one of thefollowing structures:

wherein: R^(AB2) can be selected from hydrogen, halogen and NHR^(JB2),wherein R^(JB2) can be selected from hydrogen, —C(═O)R^(KB2) and—C(═O)OR^(LB2); R^(BB2) can be halogen or NHR^(WB2), wherein R^(WB2) canbe selected from hydrogen, an optionally substituted C₁₋₆ alkyl, anoptionally substituted C₂₋₆ alkenyl, an optionally substituted C₃₋₈cycloalkyl, —C(═O)R^(MB2) and —C(═O)OR^(NB2); R^(CB2) can be hydrogen orNHR^(OB2), wherein R^(OB2) can be selected from hydrogen, —C(═O)R^(PB2)and —C(═O)OR^(QB2); R^(DB2) can be selected from hydrogen, halogen, anoptionally substituted C₁₋₆ alkyl, an optionally substituted C₂₋₆alkenyl and an optionally substituted C₂₋₆ alkynyl; R^(EB2) can beselected from hydrogen, hydroxy, an optionally substituted C₁₋₆ alkyl,an optionally substituted C₃₋₈ cycloalkyl, —C(═O)R^(RB2) and—C(═O)OR^(SB2); R^(FB2) can be selected from hydrogen, halogen, anoptionally substituted C₁₋₆ alkyl, an optionally substituted C₂₋₆alkenyl and an optionally substituted C₂₋₆ alkynyl; Y^(2B) and Y^(3B)can be independently N (nitrogen) or CR^(IB2), wherein R^(IB2) can beselected from hydrogen, halogen, an optionally substituted C₁₋₆-alkyl,an optionally substituted C₂₋₆-alkenyl and an optionally substitutedC₂₋₆-alkynyl; R^(GB2) can be an optionally substituted C₁₋₆ alkyl;R^(HB2) can be hydrogen or NHR^(TB2), wherein R^(TB2) can beindependently selected from hydrogen, —C(═O)R^(UB2) and —C(═O)OR^(VB2);and R^(KB2), R^(LB2), R^(MB2), R^(NB2), R^(PB2), R^(QB2), R^(RB2),R^(SB2), R^(UB2) and R^(VB2) can be independently selected from C₁₋₆alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₆ cycloalkyl, C₃₋₆ cycloalkenyl,C₆₋₁₀ aryl, heteroaryl, heteroalicyclyl, aryl(C₁₋₆ alkyl),heteroaryl(C₁₋₆ alkyl) and heteroalicyclyl(C₁₋₆ alkyl). In someembodiments, the structures shown above can be modified by replacing oneor more hydrogens with substituents selected from the list ofsubstituents provided for the definition of “substituted.”

In some embodiments, B^(1B) can be

In other embodiments, B^(1B) can be

In still other embodiments, B^(1B) can be

such as

In yet still other embodiments, B^(1B) can be

for example,

In some embodiments, R^(DB2) can be hydrogen. In other embodiments,B^(1B) can be

In some embodiments, R^(BB2) can be NH₂. In other embodiments, R^(BB2)can be NHR^(WB2), wherein R^(WB2) can be —C(═O)R^(MB2) or—C(═O)OR^(NB2). In still other embodiments, B^(1B) can be

In some embodiments, B^(1B) can be

In some embodiments, a compound of Formula (II) can have the followingstructure:

or a pharmaceutically acceptable salt of the foregoing. In someembodiments of this paragraph, B^(1B) can be an optionally substitutedpurine base. In other embodiments of this paragraph, B^(1B) can be anoptionally substituted pyrimidine base. In some embodiments of thisparagraph, B^(1B) can be guanine. In other embodiments of thisparagraph, B^(1B) can be thymine. In still other embodiments of thisparagraph, B^(1B) can be cytosine. In yet still other embodiments ofthis paragraph, B^(1B) can be uracil. In some embodiments of thisparagraph, B^(1B) can be adenine. In some embodiments of this paragraph,Z^(1B) can be oxygen. In some embodiments of this paragraph, Z^(1B) canbe sulfur. In still other embodiments of this paragraph, R^(1B) can bealkylcarbonyloxyalkoxy.

In some embodiments, the compound can be a compound of Formula (III), ora pharmaceutically acceptable salt thereof, wherein: B^(1C) can be anoptionally substituted heterocyclic base or an optionally substitutedheterocyclic base with a protected amino group; R^(1C) and R^(2C) can beindependently selected from O⁻, OH, an optionally substituted C₁₋₆alkoxy,

an optionally substituted N-linked amino acid and an optionallysubstituted N-linked amino acid ester derivative; R^(3C) can be selectedfrom an optionally substituted C₁₋₆ alkyl, an optionally substitutedC₂₋₆ alkenyl, an optionally substituted C₂₋₆ alkynyl, an optionallysubstituted —O—C₁₋₆ alkyl, an optionally substituted —O—C₃₋₆ alkenyl, anoptionally substituted —O—C₃₋₆ alkynyl, an optionally substituted C₃₋₆cycloalkyl and cyano; R^(4C) can be selected from OH, —OC(═O)R″^(C) andan optionally substituted O-linked amino acid; R^(5C) can be a halogen;R^(6C) can be hydrogen or halogen; R^(9C), R^(10C), R^(12C) and R^(13C)can be independently selected from hydrogen, an optionally substitutedC₁₋₂₄ alkyl and an optionally substituted aryl; R^(11C) and R^(14C) canbe independently selected from hydrogen, an optionally substituted C₁₋₂₄alkyl, an optionally substituted aryl, an optionally substituted—O—C₁₋₂₄ alkyl and an optionally substituted —O-aryl; R^(15C) can beselected from hydrogen, an optionally substituted C₁₋₂₄ alkyl and anoptionally substituted aryl; ------- can be a single bond or a doublebond; when ------- is a single bond, each R^(7C) and each R^(8C) can beindependently hydrogen or halogen; and when ------- is a double bond,each R^(7C) is absent and each R^(8C) can be independently hydrogen orhalogen; Z^(1C) can be O (oxygen) or S (sulfur); and R″^(C) can be anoptionally substituted C₁₋₂₄-alkyl.

In some embodiments, can be a single bond such that Formula (III) hasthe structure

wherein each R^(7C) and each R^(8C) can be independently hydrogen orhalogen. In some embodiments, the R^(7C) and the R^(8C) groups can allbe hydrogen. In other embodiments, one R^(7C) can be halogen, one R^(7C)can be hydrogen and both R^(8C) groups can all be hydrogen. In stillother embodiments, one R^(7C) can be halogen, one R^(7C) can behydrogen, one R^(8C) can be halogen and one R^(8C) can be hydrogen. Insome embodiments, the carbon adjacent to the phosphorus and the5′-carbon can each be independently a (S)-chiral center. In someembodiments, the carbon adjacent to the phosphorus and the 5′-carbon caneach be independently a (R)-chiral center.

In some embodiments, can be a double bond such that Formula (III) hasthe structure

wherein each R^(7C) is absent and each R^(8C) can be independentlyhydrogen or halogen. In some embodiments, both R^(8C) groups can behydrogen. In other embodiments, one R^(8C) can be halogen and the otherR^(8C) can be hydrogen. In some embodiments, both R^(8C) groups can behalogen. In some embodiments, the double bond has a (4-configuration. Insome embodiments, the double bond has a (E)-configuration.

In some embodiments, R^(1C) and/or R^(2C) can be O⁻. In otherembodiments, R^(1C) and/or R^(2C) can be OH. In some embodiments, R^(1C)and R^(2C) can be both OH.

In some embodiments, R^(1C) and/or R^(2C) can be

wherein R^(9C) and R^(10C) can be independently selected from hydrogen,an optionally substituted C₁₋₂₄ alkyl and an optionally substitutedaryl; and R^(11C) can be selected from hydrogen, an optionallysubstituted C₁₋₂₄ alkyl, an optionally substituted aryl, an optionallysubstituted —O—C₁₋₂₄ alkyl and an optionally substituted —O-aryl. Insome embodiments, R^(9C) and R^(10C) can be hydrogen. In otherembodiments, at least one of R^(9C) and R^(10C) can be an optionallysubstituted C₁₋₂₄ alkyl or an optionally substituted aryl. In someembodiments, R^(11C) can be an optionally substituted C₁₋₂₄ alkyl. Inother embodiments, R^(11C) can be an optionally substituted aryl. Instill other embodiments, R^(11C) can be an optionally substituted—O—C₁₋₂₄ alkyl or an optionally substituted —O-aryl. In someembodiments, R^(1C) and R^(2C) can be both

In some embodiments, R^(1C) and/or R^(2C) can be

wherein R^(12C) and R^(13C) can be independently selected from hydrogen,an optionally substituted C₁₋₂₄ alkyl and an optionally substitutedaryl; R^(14C) can be independently selected from hydrogen, an optionallysubstituted C₁₋₂₄ alkyl, an optionally substituted aryl, an optionallysubstituted —O—C₁₋₂₄ alkyl and an optionally substituted —O-aryl; andZ^(1C) can be independently O (oxygen) or S (sulfur). In someembodiments, R^(12C) and R^(13C) can be hydrogen. In other embodiments,at least one of R^(12C) and R^(13C) can be an optionally substitutedC₁₋₂₄ alkyl or an optionally substituted aryl. In some embodiments,R^(14C) can be an optionally substituted C₁₋₂₄ alkyl. In otherembodiments, R^(14C) can be an optionally substituted aryl. In stillother embodiments, R^(14C) can be an optionally substituted —O—C₁₋₂₄alkyl or an optionally substituted —O-aryl. In some embodiments, Z^(1C)can be O (oxygen). In other embodiments, Z^(1C) can be or S (sulfur). Insome embodiments, R^(1C) and/or R^(2C) can beisopropylcarbonyloxymethoxy. In some embodiments, R^(1C) and/or R^(2C)can be pivaloyloxymethoxy. In some embodiments, R^(1C) and R^(2C) can beboth

In some embodiments, R^(1C) and R^(2C) can be bothisopropylcarbonyloxymethoxy. In other embodiments, R^(1C) and R^(2C) canbe both pivaloyloxymethoxy.

In some embodiments, R^(1C) and/or R^(2C) can be

In some embodiments, R^(15C) can be hydrogen. In other embodiments,R^(15C) can be an optionally substituted C₁₋₂₄ alkyl. In still otherembodiments, R^(15C) can be an optionally substituted aryl. In someembodiments, R^(15C) can be a C₁₋₆ alkyl, for example, methyl, ethyl,n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl (branched andstraight-chained), and hexyl (branched and straight-chained). In someembodiments, R^(1C) and R^(2C) can be both

In some embodiments, R^(1C) and/or R^(2C) can be an optionallysubstituted N-linked amino acid or an optionally substituted N-linkedamino acid ester derivative. For example, R^(1C) and/or R^(2C) can beoptionally substituted version of the following: alanine, asparagine,aspartate, cysteine, glutamate, glutamine, glycine, proline, serine,tyrosine, arginine, histidine, isoleucine, leucine, lysine, methionine,phenylalanine, threonine, tryptophan, valine and ester derivativesthereof. In some embodiments, R^(1C) and/or R^(2C) can be selected fromalanine isopropyl ester, alanine cyclohexyl ester, alanine neopentylester, valine isopropyl ester and leucine isopropyl ester. In someembodiments, R^(1C) and/or R^(2C) can have the structure

wherein R^(19C) can be selected from hydrogen, an optionally substitutedC₁₋₆-alkyl, an optionally substituted C₃₋₆ cycloalkyl, an optionallysubstituted aryl, an optionally substituted aryl(C₁₋₆ alkyl) and anoptionally substituted haloalkyl; R^(20C) can be selected from hydrogen,an optionally substituted C₁₋₆ alkyl, an optionally substituted C₁₋₆haloalkyl, an optionally substituted C₃₋₆ cycloalkyl, an optionallysubstituted C₆ aryl, an optionally substituted C₁₀ aryl and anoptionally substituted aryl(C₁₋₆ alkyl); and R^(21C) can be hydrogen oran optionally substituted C₁₋₄-alkyl; or R^(20C) and R^(21C) can betaken together to form an optionally substituted C₃₋₆ cycloalkyl.

When R^(20C) is substituted, R^(20C) can be substituted with one or moresubstituents selected from N-amido, mercapto, alkylthio, an optionallysubstituted aryl, hydroxy, an optionally substituted heteroaryl,O-carboxy, and amino. In some embodiments, R^(20C) can be anunsubstituted C₁₋₆-alkyl, such as those described herein. In someembodiments, R^(20C) can be hydrogen. In other embodiments, R^(20C) canbe methyl. In some embodiments, R^(19C) can be an optionally substitutedC₁₋₆ alkyl. Examples of optionally substituted C₁₋₆-alkyls includeoptionally substituted variants of the following: methyl, ethyl,n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl (branched andstraight-chained), and hexyl (branched and straight-chained). In someembodiments, R^(19C) can be methyl or isopropyl. In some embodiments,R^(19C) can be ethyl or neopentyl. In other embodiments, R^(19C) can bean optionally substituted C₃₋₆ cycloalkyl. Examples of optionallysubstituted C₃₋₆ cycloalkyl include optionally substituted variants ofthe following: cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl. Inan embodiment, R^(19C) can be an optionally substituted cyclohexyl. Instill other embodiments, R^(19C) can be an optionally substituted aryl,such as phenyl and naphthyl. In yet still other embodiments, R^(19C) canbe an optionally substituted aryl(C₁₋₆ alkyl). In some embodiments,R^(19C) can be an optionally substituted benzyl. In some embodiments,R^(19C) can be an optionally substituted C₁₋₆ haloalkyl, for example,CF₃. In some embodiments, R^(21C) can be hydrogen. In other embodiments,R^(21C) can be an optionally substituted C₁₋₄-alkyl, such as methyl,ethyl, n-propyl, isopropyl, n-butyl, isobutyl and tert-butyl. In anembodiment, R^(21C) can be methyl. In some embodiments, R^(20C) andR^(21C) can be taken together to form an optionally substituted C₃₋₆cycloalkyl. Examples of optionally substituted C₃₋₆ cycloalkyl includeoptionally substituted variants of the following: cyclopropyl,cyclobutyl, cyclopentyl, and cyclohexyl. Depending on the groups thatare selected for R^(20C) and R^(21C), the carbon to which R^(20C) andR^(21C) are attached may be a chiral center. In some embodiment, thecarbon to which R^(20C) and R^(21C) are attached may be a (R)-chiralcenter. In other embodiments, the carbon to which R^(20C) and R^(21C)are attached may be a (S)-chiral center.

Examples of suitable

groups include the following:

In some embodiments, R^(1C) and R^(2C) can be the same. In otherembodiments, R^(1C) and R^(2C) can be different.

In some embodiments, R^(1C) can be

can be O⁻ or OH, wherein R^(16C), R^(17C) and R^(18C) can be absent orhydrogen; and n can be 0 or 1. Those skilled in the art understand thatwhen R^(16C), R^(17C) and/or R^(18C) are absent, the associated oxygenwill be negatively charge. In some embodiments, when n is 0, thecompound of Formula (III) will be a diphosphate. In other embodiments,when n is 1, the compound of Formula (III) will be a triphosphate.

A variety of substituents can be present at the 4′-position of thepentose ring. In some embodiments, R^(3C) can be an optionallysubstituted C₁₋₆ alkyl. Examples of suitable C₁₋₆ alkyls include methyl,ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl(branched and straight-chained), and hexyl (branched andstraight-chained). In some embodiments, R^(3C) can be an unsubstitutedC₁₋₆ alkyl. In other embodiments, R^(3C) can be a substituted C₁₋₆alkyl. For example, R^(3C) can be a halogen substituted C₁₋₆ alkyl. Inother embodiments, R^(3C) can be an optionally substituted C₂₋₆ alkenyl.In some embodiments, R³ can be a substituted C₂₋₆ alkenyl. In otherembodiments, R^(3C) can be an unsubstituted C₂₋₆ alkenyl. For example,R^(3C) can be ethenyl, propenyl or allenyl. In still other embodiments,R^(3C) can be an optionally substituted C₂₋₆ alkynyl. In someembodiments, R^(3C) can be a substituted C₂₋₆ alkynyl. In otherembodiments, R^(3C) can be an unsubstituted C₂₋₆ alkynyl. Suitable C₂₋₆alkynyls include ethynyl and propynyl. In yet still other embodiments,R^(3C) can be an optionally substituted C₃₋₆ cycloalkyl. In someembodiments, R^(3C) can be a substituted C₃₋₆ cycloalkyl. In otherembodiments, R^(3C) can be an unsubstituted C₃₋₆ cycloalkyl. Anon-limiting list of C₃₋₆ cycloalkyls include cyclopropyl, cyclobutyl,cyclopentyl and cyclohexyl. In some embodiments, R^(3C) can be anoptionally substituted —O—C₁₋₆ alkyl. In some embodiments, R^(3C) can bea substituted —O—C₁₋₆ alkyl. In other embodiments, R^(3C) can be anunsubstituted —O—C₁₋₆ alkyl. Examples of suitable O—C₁₋₆ alkyl groupsinclude methoxy, ethoxy, n-propoxy, iso-propoxy, n-butoxy, isobutoxy,tert-butoxy, pentoxy (branched and straight-chained), and hexoxy(branched and straight-chained). In other embodiments, R³C can be anoptionally substituted —O—C₃₋₆ alkenyl. In some embodiments, R^(3C) canbe a substituted —O—C₃₋₆ alkenyl. In other embodiments, R^(3C) can be anunsubstituted —O—C₃₋₆ alkenyl. In still other embodiments, R^(3C) can bean optionally substituted —O—C₃₋₆ alkynyl. In some embodiments, R^(3C)can be a substituted —O—C₃₋₆ alkynyl. In other embodiments, R³C can bean unsubstituted —O—C₃₋₆ alkynyl. In yet still other embodiments, R^(3C)can be cyano. The substituents that can be present on the 3′-position ofthe pentose ring can vary. In some embodiments, R^(4C) can be OH. Inother embodiments, R^(4C) can be an optionally substituted O-linkedamino acid. Examples of suitable O-linked amino acids include alanine,asparagine, aspartate, cysteine, glutamate, glutamine, glycine, proline,serine, tyrosine, arginine, histidine, isoleucine, leucine, lysine,methionine, phenylalanine, threonine, tryptophan and valine. Additionalexamples of suitable amino acids include, but are not limited to,ornithine, hypusine, 2-aminoisobutyric acid, dehydroalanine,gamma-aminobutyric acid, citrulline, beta-alanine, alpha-ethyl-glycine,alpha-propyl-glycine and norleucine. In some embodiments, the O-linkedamino acid can have the structure

wherein R^(22C) can be selected from hydrogen, an optionally substitutedC₁₋₆ alkyl, an optionally substituted C₁₋₆ haloalkyl, an optionallysubstituted C₃₋₆ cycloalkyl, an optionally substituted C₆ aryl, anoptionally substituted C₁₀ aryl and an optionally substituted aryl(C₁₋₆alkyl); and R^(23C) can be hydrogen or an optionally substitutedC₁₋₄-alkyl; or R^(22C) and R^(23C) can be taken together to form anoptionally substituted C₃₋₆ cycloalkyl.

When R^(22C) is substituted, R^(22C) can be substituted with one or moresubstituents selected from N-amido, mercapto, alkylthio, an optionallysubstituted aryl, hydroxy, an optionally substituted heteroaryl,O-carboxy, and amino. In some embodiments, R^(22C) can be anunsubstituted C₁₋₆-alkyl, such as those described herein. In someembodiments, R^(22C) can be hydrogen. In other embodiments, R^(22C) canbe methyl. In some embodiments, R^(23C) can be hydrogen. In otherembodiments, R^(23C) can be an optionally substituted C₁₋₄-alkyl, suchas methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl and tert-butyl.In an embodiment, R^(23C) can be methyl. Depending on the groups thatare selected for R^(22C) and R^(23C), the carbon to which R^(22C) andR^(23C) are attached may be a chiral center. In some embodiment, thecarbon to which R^(22C) and R^(23C) are attached may be a (R)-chiralcenter. In other embodiments, the carbon to which R^(22C) and R^(23C)are attached may be a (S)-chiral center.

Examples of suitable

include the following:

In still other embodiments, R^(4C) can be —OC(═O)R″^(C), wherein R″^(C)can be an optionally substituted C₁₋₂₄ alkyl. In some embodiments,R″^(C) can be a substituted C₁₋₁₂ alkyl. In other embodiments, R″^(C)can be an unsubstituted C₁₋₁₂ alkyl. In still other embodiments, R″^(C)can be a substituted C₁₋₈ alkyl. In yet still other embodiments, R″^(C)can be an unsubstituted C₁₋₈ alkyl. In some embodiments, R^(4C) can bean optionally substituted acyl. In other embodiments, R^(4C) can be—OC(═O)R″^(C), wherein R″^(C) can be selected from an optionallysubstituted C₁₋₁₂ alkyl, an optionally substituted C₂₋₁₂ alkenyl, anoptionally substituted C₂₋₁₂ alkynyl, an optionally substituted C₃₋₈cycloalkyl, an optionally substituted C₅₋₈ cycloalkenyl, an optionallysubstituted C₆₋₁₀ aryl, an optionally substituted heteroaryl, anoptionally substituted heterocyclyl, an optionally substituted aryl(C₁₋₆alkyl), an optionally substituted heteroaryl(C₁₋₆ alkyl) and anoptionally substituted heterocyclyl(C₁₋₆ alkyl). In some embodiments,R″^(C) can be a substituted C₁₋₁₂ alkyl. In other embodiments, R″^(C)can be an unsubstituted C₁₋₁₂ alkyl.

A variety of substituents can also be present at the 2′-position of thepentose ring. In some embodiments, R^(6C) can be hydrogen. In otherembodiments, R^(6C) can be halogen, such as fluoro. In some embodiments,R^(5C) can be halogen, such as fluoro. In some embodiments, R^(6C) canbe hydrogen and R^(5C) can be halogen. In other embodiments, R^(5C) andR^(6C) can be both halogen. For example, R^(5C) and R^(6C) can be bothfluoro.

Various optionally substituted heterocyclic bases can be attached to thepentose ring. In some embodiments, one or more of the amine and/or aminogroups may be protected with a suitable protecting group. For example,an amino group may be protected by transforming the amine and/or aminogroup to an amide or a carbamate. In some embodiments, an optionallysubstituted heterocyclic base or an optionally substituted heterocyclicbase with one or more protected amino groups can have one of thefollowing structures:

wherein: R^(AC2) can be selected from hydrogen, halogen and NHR^(JC2),wherein R^(JC2) can be selected from hydrogen, can be halogen orNHR^(WC2), wherein R^(WC2) can be selected from hydrogen, an optionallysubstituted C₁₋₆ alkyl, an optionally substituted C₂₋₆ alkenyl, anoptionally substituted C₃₋₈ cycloalkyl, —C(═O)R^(MC2) and—C(═O)OR^(NC2); R^(CC2) can be hydrogen or NHR^(OC2), wherein R^(OC2)can be selected from hydrogen, —C(═O)R^(PC2) and —C(═O)OR^(QC2); R^(DC2)can be selected from hydrogen, halogen, an optionally substituted C₁₋₆alkyl, an optionally substituted C₂₋₆ alkenyl and an optionallysubstituted C₂₋₆ alkynyl; R^(EC2) can be selected from hydrogen,hydroxy, an optionally substituted C₁₋₆ alkyl, an optionally substitutedC₃₋₈ cycloalkyl, —C(═O)R^(RC2) and —C(═O)OR^(SC2); R^(FC2) can beselected from hydrogen, halogen, an optionally substituted C₁₋₆ alkyl,an optionally substituted C₂₋₆ alkenyl and an optionally substitutedC₂₋₆ alkynyl; Y^(2C) and Y^(3C) can be independently N (nitrogen) orCR^(IC2), wherein R^(IC2) can be selected from hydrogen, halogen, anoptionally substituted C₁₋₆-alkyl, an optionally substitutedC₂₋₆-alkenyl and an optionally substituted C₂₋₆-alkynyl; R^(GC2) can bean optionally substituted C₁₋₆ alkyl; R^(HC2) can be hydrogen orNHR^(TC2), wherein R^(TC2) can be independently selected from hydrogen,—C(═O)R^(UC2) and —C(═O)OR^(VC2); and R^(KC2), R^(LC2), R^(MC2),R^(NC2), R^(PC2), R^(QC2), R^(RC2), R^(SC2), R^(UC2) and R^(VC2) can beindependently selected from C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₆cycloalkyl, C₃₋₆ cycloalkenyl, C₆₋₁₀ aryl, heteroaryl, heteroalicyclyl,aryl(C₁₋₆ alkyl), heteroaryl(C₁₋₆ alkyl) and heteroalicyclyl(C₁₋₆alkyl). In some embodiments, the structures shown above can be modifiedby replacing one or more hydrogens with substituents selected from thelist of substituents provided for the definition of “substituted.”

In some embodiments, B^(1C) can be

In other embodiments, B^(1C) can be

In still other embodiments, B^(1C) can be

such as

In yet still other embodiments, B^(1C) can be

for example,

In some embodiments, R^(DC2) can be hydrogen. In other embodiments,B^(1C) can be

In some embodiments, R^(BC2) can be NH₂. In other embodiments, R^(BC2)can be NHR^(WC2), wherein R^(WC2) can be —C(═O)R^(MC2) or—C(═O)OR^(NC2). In still other embodiments, B^(1C) can be

In some embodiments, B^(1C) can be

In some embodiments, the compound of Formula (III) can have one of thefollowing structures:

In some embodiments of this paragraph, B^(1C) can be an optionallysubstituted purine base. In other embodiments of this paragraph, B^(1C)can be an optionally substituted pyrimidine base. In some embodiments ofthis paragraph, B^(1C) can be guanine. In other embodiments of thisparagraph, B^(1C) can be thymine. In still other embodiments of thisparagraph, B^(1C) can be cytosine. In yet still other embodiments ofthis paragraph, B^(1C) can be uracil. In some embodiments of thisparagraph, B^(1C) can be adenine. In some embodiments of this paragraph,R^(1C) and R^(2C) can each be an optionally substituted C₁₋₄ alkyl. Inother embodiments of this paragraph, R^(1A) can be an optionallysubstituted acyl. In still other embodiments of this paragraph, R^(1C)and R^(2C) can form a mono-, di- or tri-phosphate. In yet otherembodiments of this paragraph, R^(1C) and R^(2C) can each be analkylcarbonyloxyalkoxy. In some embodiments of this paragraph, R^(4C)can be OH. In some embodiments of this paragraph, R^(5C) can be F andR^(6C) can be hydrogen.

Examples of suitable compounds of Formula (I) include, but are notlimited to the following:

or a pharmaceutically acceptable salt of the foregoing.

Additional examples of a compound of Formula (I) include the following:

or a pharmaceutically acceptable salt of the foregoing.

Further examples of a compound of Formula (I) include, but are notlimited to the following:

or a pharmaceutically acceptable salt of the foregoing.

Examples of a compound of Formula (II) include, but are not limited to,the following:

or a pharmaceutically acceptable salt of the foregoing.

Examples of a compound of Formula (III) include, but are not limited to,the following:

or a pharmaceutically acceptable salt of the foregoing.

Further examples of a compound of Formula (III) include, but are notlimited to, the following:

or a pharmaceutically acceptable salt of the foregoing.Synthesis

Compounds of Formula (I) Formula (II) and Formula (III), and thosedescribed herein may be prepared in various ways. Some compounds ofFormulae (I), (II) and (III) can be obtained commercially and/orprepared utilizing known synthetic procedures. General synthetic routesto the compounds of Formulae (I), (II) and (III), and some examples ofstarting materials used to synthesize the compounds of Formulae (I),(II) and (III) are shown and described herein. The routes shown anddescribed herein are illustrative only and are not intended, nor arethey to be construed, to limit the scope of the claims in any mannerwhatsoever. Those skilled in the art will be able to recognizemodifications of the disclosed syntheses and to devise alternate routesbased on the disclosures herein; all such modifications and alternateroutes are within the scope of the claims.

As shown in Scheme 1, compounds of Formula (I) can be prepared from anucleoside, for example, a nucleoside of Formula (A). In Scheme 1,R^(3a), R^(4a), R^(5a), and B^(1a) can be the same as R^(3A), R^(4A),R^(5A), and B^(1A) as described herein for Formula (I), and PG¹ is asuitable protecting group. A hydroxyalkyl group can be formed at the4′-position of the pentose ring using suitable conditions known to thoseskilled in the art. Examples of suitable conditions for forming ahydroxyalkyl include the use of 2-iodoxybenzoic acid (IBX) aqueousformaldehyde and sodium borohydride. A compound of Formula (B) can beoxidized to an aldehyde using a suitable oxidizing agent(s) to form acompound of Formula (C). An example of suitable oxidizing agent isDess-Martin periodinane. An optionally substituted C₂₋₆ alkenyl or anoptionally substituted C₂₋₆ alkynyl can be formed at the 4′-positionusing methods known to those skilled in the art, for example, Wittigreagent and n-BuLi, Wittig-type reactions, Peterson olefinationreaction, and Corey Fuchs reaction. An optionally substituted C₁₋₆ alkylcan be obtained by hydrogenating the unsaturated group attached to the4′-position, for example, using hydrogen over palladium on carbon.

Alternatively, a compound of Formula (B) can be transformed to ahaloalkyl using a suitable agent(s), for example, to an iodide usingimidazole, triphenylphosphine and iodine; to a fluoro usingdiethylaminosulfur trifluoride (DAST); or to a chloro usingtriphenylphosphine and carbontetrachloride in dichloroethylene (DCE). Aniodoalkyl can be transformed to an unsubstituted C₁₋₆ alkyl group usingmethods known to those skilled in the art, for example, hydrogen overpalladium on carbon. A compound of Formula (C) can be reacted withhydroxylamine to form an oxime. The oxime can be transformed to a cyanogroup using methods known to those skilled in the art, for example,using methanesulfonyl chloride.

As shown in Scheme 2, compounds of Formula (I), where R^(2A) is anoptionally substituted —O—C₁₋₆ alkyl, an optionally substituted —O—C₃₋₆alkenyl or an optionally substituted —O—C₃₋₆ alkynyl, can be preparedfrom a nucleoside, for example, a nucleoside of Formula (A). In Scheme2, R^(2a), R^(3a), R^(4a), R^(5a) and B^(1a) can be the same as R^(2A),R^(3A), R^(4A), R^(5A) and B^(1A) as described herein for Formula (I),and PG² can be a suitable protecting group. The nucleoside can undergoelimination and form an olefin having the general formula of Formula(D). A compound of Formula (D) can be treated with an iodinating reagentin the presence of lead carbonate and an alkoxy source to form acompound of Formula (E). A compound of Formula (E) can then betransformed to a compound of Formula (I) through displacement of theiodide with an oxygen nucleophile.

Compounds of Formula (I) having a phosphorus containing group attachedto the 5′-position of the pentose ring can be prepared using variousmethods known to those skilled in the art. Examples of methods are shownin Schemes 3 and 4. A phosphorus containing precursor can be coupled tothe nucleoside, for example, a compound of Formula (F) or a compound ofFormula (G). As shown in Scheme 3, following the coupling of thephosphorus containing precursor, any leaving groups can be cleaved undersuitable conditions, such as hydrolysis. Further phosphorus containinggroups can be added using methods known to those skilled in the art, forexample using a pyrophosphate.

In some embodiments, an alkoxide can be generated from a compound ofFormula (G) using an organometallic reagent, such as a Grignard reagent.The alkoxide can be coupled to the phosphorus containing precursor.Suitable Grignard reagents are known to those skilled in the art andinclude, but are not limited to, alkylmagnesium chlorides andalkylmagnesium bromides. In some embodiments, an appropriate base can beused. Examples of suitable bases include, but are not limited to, anamine base, such as an alkylamine (including mono-, di- andtri-alkylamines (e.g., triethylamine)), optionally substituted pyridines(e.g. collidine) and optionally substituted imidazoles (e.g.,N-methylimidazole)). Alternatively, a phosphorus containing precursorcan be added to the nucleoside and form a phosphite. The phosphite canbe oxidized to a phosphate using conditions known to those skilled inthe art. Suitable conditions include, but are not limited to,meta-chloroperoxybenzoic acid (MCPBA) and iodine as the oxidizing agentand water as the oxygen donor.

When compounds of Formula (I) have Z^(1A), Z^(2A) or Z^(3A) beingsulfur, the sulfur can be added in various manners known to thoseskilled in the art. In some embodiments, the sulfur can be part of thephosphorus containing precursor, for example,

Alternatively, the sulfur can be added using a sulfurization reagent.Suitable sulfurization agents are known to those skilled in the art, andinclude, but are not limited to, elemental sulfur, Lawesson's reagent,cyclooctasulfur, 3H-1,2-Benzodithiole-3-one-1,1-dioxide (Beaucage'sreagent),3-((N,N-dimethylaminomethylidene)amino)-3H-1,2,4-dithiazole-5-thione(DDTT) and bis(3-triethoxysilyl)propyl-tetrasulfide (TEST).

Suitable phosphorus containing precursors can be commercially obtainedor prepared by synthetic methods known to those skilled in the art.Examples of general structures of phosphorus containing precursors areshown in Schemes 3 and 4.

A method for forming a compound of Formula (II) is shown in Scheme 5. InScheme 5, R^(1b), R^(2b), R^(3b), R^(4b) and B^(1b) can be the same asR^(1B), R^(2B), R^(3B), R^(4B) and B^(1B) as described herein forFormula (II), each L¹ can be a halogen, a sulfonate ester or an amine(mono- or di-substituted), and X can be oxygen or sulfur. As shown inScheme 5, a compound having a hydroxy group attached to the 3′-carbonand a hydroxy group attached to the 5′-carbon can be reacted with acompound having the formula, (R^(1b))P(L¹)₂, in the presence of a base,to produce a phosphite compound. Suitable bases are known to thoseskilled in the art and described herein. The phosphorus can then beoxidized to phosphorus(V) using a suitable oxidizing agent, to produce acompound where X is O (oxygen). Alternatively, the phosphite compoundcan be reacted with a sulfurization reagent to produce a compound whereX is S (sulfur). Suitable oxidizing and sulfurization agents are knownto those skilled in the art. For example, the oxidation can be carriedout using iodine as the oxidizing agent and water as the oxygen donor.Suitable sulfurization agents are described herein.

A method for forming a compound of Formula (III) is shown in Scheme 6.In Scheme 6, R^(1c), R^(2c), R^(3c), R^(4c), R^(5c), R^(6c) and B^(1c)can be the same as R^(1C), R^(2C), R^(3C), R^(4C), R^(5C), R^(6C) andB^(1C) as described herein for Formula (III), and R^(7C) and R^(8C) arenot shown. The oxygen attached to the 5′-carbon of the compound ofFormula (H) can be oxidized to a ketone using methods and reagents knownto those skilled in the art. For example, an oxidizing agent, such asDess-Martin periodinane, can be utilized. A phosphorus-containingreagent can then be added to a compound of Formula (J) in the presenceof a strong base (e.g., sodium hydride). The double bond can behydrogenated, for example using hydrogen gas or Pd/C, to a single bond.Additional phosphates can be added via phosphorylation to form a di- ortri-phosphate using suitable reagents, such as a pyrophosphate (e.g.,tetrabutylammonium pyrophosphate).

An acyl group can be added to the 5′-position and/or the 3′-position ofa compound of Formula (I) or (III) using methods known to those skilledin the art. One suitable method is using an anhydride in pyridine.

During the synthesis of any of the compounds described herein, ifdesired, any hydroxy groups attached to the pentose ring, and any —NHand/or NH₂ groups present on the B^(1a), B^(1b) and B^(1c) can beprotected with one or more suitable protecting groups. Suitableprotecting groups are described herein. For example, when R^(3a) and/orR^(4c) is a hydroxy group, R^(3a) and/or R^(4c) can be protected with atriarylmethyl group or a silyl group. Likewise, any —NH and/or NH₂groups present on the B^(1a), B^(1b) and B^(1c) can be protected, suchas with a triarylmethyl and a silyl group(s). Examples of triarylmethylgroups include but are not limited to, trityl, monomethoxytrityl (MMTr),4,4′-dimethoxytrityl (DMTr), 4,4′,4″-trimethoxytrityl (TMTr),4,4′,4″-tris-(benzoyloxy) trityl (TBTr),4,4′,4″-tris(4,5-dichlorophthalimido) trityl (CPTr),4,4′,4″-tris(levulinyloxy) trityl (TLTr),p-anisyl-1-naphthylphenylmethyl, di-o-anisyl-1-naphthylmethyl,p-tolyldipheylmethyl, 3-(imidazolylmethyl)-4,4′-dimethoxytrityl,9-phenylxanthen-9-yl (Pixyl), 9-(p-methoxyphenyl)xanthen-9-yl (Mox),4-decyloxytrityl, 4-hexadecyloxytrityl, 4,4′-dioctadecyltrityl,9-(4-octadecyloxyphenyl)xanthen-9-yl,1,1′-bis-(4-methoxyphenyl)-1′-pyrenylmethyl,4,4′,4″-tris-(tert-butylphenyl)methyl (TTTr) and4,4′-di-3,5-hexadienoxytrityl. Examples of silyl groups include, but arenot limited to, trimethylsilyl (TMS), tert-butyldimethylsilyl (TBDMS),triisopropylsilyl (TIPS), tert-butyldiphenylsilyl (TBDPS),tri-iso-propylsilyloxymethyl and [2-(trimethylsilyl)ethoxy]methyl.Alternatively, R^(3a) and R^(4a) and/or R^(4c) and R^(5c) can beprotected by a single achiral or chiral protecting group, for example,by forming an orthoester, a cyclic acetal or a cyclic ketal. Suitableorthoesters include methoxymethylene acetal, ethoxymethylene acetal,2-oxacyclopentylidene orthoester, dimethoxymethylene orthoester,1-methoxyethylidene orthoester, 1-ethoxyethylidene orthoester,methylidene orthoester, phthalide orthoester 1,2-dimethoxyethylideneorthoester, and alpha-methoxybenzylidene orthoester; suitable cyclicacetals include methylene acetal, ethylidene acetal, t-butylmethylideneacetal, 3-(benzyloxy)propyl acetal, benzylidene acetal,3,4-dimethoxybenzylidene acetal and p-acetoxybenzylidene acetal; andsuitable cyclic ketals include 1-t-butylethylidene ketal,1-phenylethylidene ketal, isopropylidene ketal, cyclopentylidene ketal,cyclohexylidene ketal, cycloheptylidene ketal and1-(4-methoxyphenyl)ethylidene ketal. Those skilled in the art willappreciate that groups attached to the pentose ring and any —NH and/orNH₂ groups present on the B^(1a), B^(1b) and B^(1c) can be protectedwith various protecting groups, and any protecting groups present can beexchanged for other protecting groups. The selection and exchange of theprotecting groups is within the skill of those of ordinary skill in theart. Any protecting group(s) can be removed by methods known in the art,for example, with an acid (e.g., a mineral or an organic acid), a baseor a fluoride source.

Pharmaceutical Compositions

Some embodiments described herein relates to a pharmaceuticalcomposition, that can include an effective amount of one or morecompounds described herein (e.g., a compound of Formula (I), a compoundof Formula (II) and/or a compound of Formula (III), or apharmaceutically acceptable salt of the foregoing) and apharmaceutically acceptable carrier, diluent, excipient or combinationthereof.

The term “pharmaceutical composition” refers to a mixture of one or morecompounds disclosed herein with other chemical components, such asdiluents or carriers. The pharmaceutical composition facilitatesadministration of the compound to an organism. Pharmaceuticalcompositions can also be obtained by reacting compounds with inorganicor organic acids such as hydrochloric acid, hydrobromic acid, sulfuricacid, nitric acid, phosphoric acid, methanesulfonic acid, ethanesulfonicacid, p-toluenesulfonic acid, and salicylic acid. Pharmaceuticalcompositions will generally be tailored to the specific intended routeof administration.

The term “physiologically acceptable” defines a carrier, diluent orexcipient that does not abrogate the biological activity and propertiesof the compound.

As used herein, a “carrier” refers to a compound that facilitates theincorporation of a compound into cells or tissues. For example, withoutlimitation, dimethyl sulfoxide (DMSO) is a commonly utilized carrierthat facilitates the uptake of many organic compounds into cells ortissues of a subject.

As used herein, a “diluent” refers to an ingredient in a pharmaceuticalcomposition that lacks pharmacological activity but may bepharmaceutically necessary or desirable. For example, a diluent may beused to increase the bulk of a potent drug whose mass is too small formanufacture and/or administration. It may also be a liquid for thedissolution of a drug to be administered by injection, ingestion orinhalation. A common form of diluent in the art is a buffered aqueoussolution such as, without limitation, phosphate buffered saline thatmimics the composition of human blood.

As used herein, an “excipient” refers to an inert substance that isadded to a pharmaceutical composition to provide, without limitation,bulk, consistency, stability, binding ability, lubrication,disintegrating ability etc., to the composition. A “diluent” is a typeof excipient.

The pharmaceutical compositions described herein can be administered toa human patient per se, or in pharmaceutical compositions where they aremixed with other active ingredients, as in combination therapy, orcarriers, diluents, excipients or combinations thereof. Properformulation is dependent upon the route of administration chosen.Techniques for formulation and administration of the compounds describedherein are known to those skilled in the art.

The pharmaceutical compositions disclosed herein may be manufactured ina manner that is itself known, e.g., by means of conventional mixing,dissolving, granulating, dragee-making, levigating, emulsifying,encapsulating, entrapping or tableting processes. Additionally, theactive ingredients are contained in an amount effective to achieve itsintended purpose. Many of the compounds used in the pharmaceuticalcombinations disclosed herein may be provided as salts withpharmaceutically compatible counterions.

Multiple techniques of administering a compound exist in the artincluding, but not limited to, oral, rectal, topical, aerosol, injectionand parenteral delivery, including intramuscular, subcutaneous,intravenous, intramedullary injections, intrathecal, directintraventricular, intraperitoneal, intranasal and intraocularinjections.

One may also administer the compound in a local rather than systemicmanner, for example, via injection of the compound directly into theinfected area, often in a depot or sustained release formulation.Furthermore, one may administer the compound in a targeted drug deliverysystem, for example, in a liposome coated with a tissue-specificantibody. The liposomes will be targeted to and taken up selectively bythe organ.

The compositions may, if desired, be presented in a pack or dispenserdevice which may contain one or more unit dosage forms containing theactive ingredient. The pack may for example comprise metal or plasticfoil, such as a blister pack. The pack or dispenser device may beaccompanied by instructions for administration. The pack or dispensermay also be accompanied with a notice associated with the container inform prescribed by a governmental agency regulating the manufacture,use, or sale of pharmaceuticals, which notice is reflective of approvalby the agency of the form of the drug for human or veterinaryadministration. Such notice, for example, may be the labeling approvedby the U.S. Food and Drug Administration for prescription drugs, or theapproved product insert. Compositions that can include a compounddescribed herein formulated in a compatible pharmaceutical carrier mayalso be prepared, placed in an appropriate container, and labeled fortreatment of an indicated condition.

Methods of Use:

Some embodiments described herein relate to a method of ameliorating,treating and/or preventing a viral infection selected from aparamyxovirus viral infection and an orthomyxovirus viral infection,which can include administering to a subject an effective amount of oneor more compounds described herein, or a pharmaceutical composition thatincludes one or more compounds described herein (e.g., a compound ofFormula (I), a compound of Formula (II) and/or a compound of Formula(III), or a pharmaceutically acceptable salt of the foregoing). In someembodiments, the subject is identified as suffering from the viralinfection (for example, a paramyxovirus viral infection or anorthomyxovirus viral infection).

Other embodiments described herein relate to a method of inhibitingviral replication of a virus selected from a paramyxovirus and anorthomyxovirus, which can include contacting a cell infected with thevirus with an effective amount of a compound of Formula (I), or apharmaceutically acceptable salt thereof, an effective amount of acompound of Formula (II), or a pharmaceutically acceptable salt thereof,an effective amount of a compound of Formula (III), or apharmaceutically acceptable salt thereof, and/or a pharmaceuticalcomposition that includes one or more compounds described herein (e.g.,a compound of Formula (I), a compound of Formula (II) and/or a compoundof Formula (III), or a pharmaceutically acceptable salt of theforegoing).

In some embodiments, an effective amount of one or more compounds ofFormula (I), or a pharmaceutically acceptable salt thereof, one or morecompounds of Formula (II), or a pharmaceutically acceptable saltthereof, an effective amount of one or more compounds of Formula (III),or a pharmaceutically acceptable salt thereof, and/or a pharmaceuticalcomposition that includes one or more compounds described herein (e.g.,a compound of Formula (I), a compound of Formula (II) and/or a compoundof Formula (III), or a pharmaceutically acceptable salt of theforegoing) can be used to treat and/or ameliorate a respiratorysyncytial viral (RSV) infection. In some embodiments, an effectiveamount of one or more compounds of Formula (I), or a pharmaceuticallyacceptable salt thereof, one or more compounds of Formula (II), or apharmaceutically acceptable salt thereof, an effective amount of one ormore compounds of Formula (III), or a pharmaceutically acceptable saltthereof, and/or a pharmaceutical composition that includes one or morecompounds described herein (e.g., a compound of Formula (I) a compoundof Formula (II) and/or a compound of Formula (III), or apharmaceutically acceptable salt of the foregoing) can be used toprevent a respiratory syncytial viral infection. In some embodiments, aneffective amount of one or more compounds of Formula (I), or apharmaceutically acceptable salt thereof, one or more compounds ofFormula (II), or a pharmaceutically acceptable salt thereof, aneffective amount of one or more compounds of Formula (III), or apharmaceutically acceptable salt thereof, and/or a pharmaceuticalcomposition that includes one or more compounds described herein (e.g.,a compound of Formula (I), a compound of Formula (II) and/or a compoundof Formula (III), or a pharmaceutically acceptable salt of theforegoing) can be used to inhibit the replication of a respiratorysyncytial virus. In some embodiments, an effective amount of one or morecompounds of Formula (I), or a pharmaceutically acceptable salt thereof,one or more compounds of Formula (II), or a pharmaceutically acceptablesalt thereof, an effective amount of one or more compounds of Formula(III), or a pharmaceutically acceptable salt thereof, and/or apharmaceutical composition that includes one or more compounds describedherein (e.g., a compound of Formula (I), a compound of Formula (II)and/or a compound of Formula (III), or a pharmaceutically acceptablesalt of the foregoing) can be used to inhibit the RSV polymerasecomplex.

In other embodiments, an effective amount of one or more compounds ofFormula (I), or a pharmaceutically acceptable salt thereof, one or morecompounds of Formula (II), or a pharmaceutically acceptable saltthereof, an effective amount of one or more compounds of Formula (III),or a pharmaceutically acceptable salt thereof, and/or a pharmaceuticalcomposition that includes one or more compounds described herein (e.g.,a compound of Formula (I) a compound of Formula (II) and/or a compoundof Formula (II), or a pharmaceutically acceptable salt of the foregoing)can be used to treat and/or ameliorate an influenza viral infection. Inother embodiments, an effective amount of one or more compounds ofFormula (I), or a pharmaceutically acceptable salt thereof, one or morecompounds of Formula (II), or a pharmaceutically acceptable saltthereof, an effective amount of one or more compounds of Formula (III),or a pharmaceutically acceptable salt thereof, and/or a pharmaceuticalcomposition that includes one or more compounds described herein (e.g.,a compound of Formula (I), a compound of Formula (II) and/or a compoundof Formula (III), or a pharmaceutically acceptable salt of theforegoing) can be used to prevent an influenza viral infection. In someembodiments, an effective amount of one or more compounds of Formula(I), or a pharmaceutically acceptable salt thereof, one or morecompounds of Formula (II), or a pharmaceutically acceptable saltthereof, an effective amount of one or more compounds of Formula (III),or a pharmaceutically acceptable salt thereof, and/or a pharmaceuticalcomposition that includes one or more compounds described herein (e.g.,a compound of Formula (I), a compound of Formula (II) and/or a compoundof Formula (III), or a pharmaceutically acceptable salt of theforegoing) can be used to inhibit the replication of an influenza virus.In some embodiments, an effective amount of one or more compounds ofFormula (I), or a pharmaceutically acceptable salt thereof, one or morecompounds of Formula (II), or a pharmaceutically acceptable saltthereof, an effective amount of one or more compounds of Formula (III),or a pharmaceutically acceptable salt thereof, and/or a pharmaceuticalcomposition that includes one or more compounds described herein (e.g.,a compound of Formula (I), a compound of Formula (II) and/or a compoundof Formula (III), or a pharmaceutically acceptable salt of theforegoing) can be used to inhibit the influenza polymerase complex.

In some embodiments, an effective amount of one or more compounds ofFormula (I), or a pharmaceutically acceptable salt thereof, one or morecompounds of Formula (II), or a pharmaceutically acceptable saltthereof, an effective amount of one or more compounds of Formula (III),or a pharmaceutically acceptable salt thereof, and/or a pharmaceuticalcomposition that includes one or more compounds described herein (e.g.,a compound of Formula (I), a compound of Formula (II) and/or a compoundof Formula (III), or a pharmaceutically acceptable salt of theforegoing) can be used to treat and/or ameliorate a hendraviralinfection and/or nipahviral infection. In some embodiments, an effectiveamount of one or more compounds of Formula (I), or a pharmaceuticallyacceptable salt thereof, one or more compounds of Formula (II), or apharmaceutically acceptable salt thereof, an effective amount of one ormore compounds of Formula (III), or a pharmaceutically acceptable saltthereof, and/or a pharmaceutical composition that includes one or morecompounds described herein (e.g., a compound of Formula (I) a compoundof Formula (II) and/or a compound of Formula (III), or apharmaceutically acceptable salt of the foregoing) can be used toprevent a hendraviral infection and/or nipahviral infection. In someembodiments, an effective amount of one or more compounds of Formula(I), or a pharmaceutically acceptable salt thereof, one or morecompounds of Formula (II), or a pharmaceutically acceptable saltthereof, an effective amount of one or more compounds of Formula (III),or a pharmaceutically acceptable salt thereof, and/or a pharmaceuticalcomposition that includes one or more compounds described herein (e.g.,a compound of Formula (I), a compound of Formula (II) and/or a compoundof Formula (III), or a pharmaceutically acceptable salt of theforegoing) can be used to inhibit the replication of a hendravirusand/or nipahvirus. In some embodiments, an effective amount of one ormore compounds of Formula (I), or a pharmaceutically acceptable saltthereof, one or more compounds of Formula (II), or a pharmaceuticallyacceptable salt thereof, an effective amount of one or more compounds ofFormula (III), or a pharmaceutically acceptable salt thereof, and/or apharmaceutical composition that includes one or more compounds describedherein (e.g., a compound of Formula (I), a compound of Formula (II)and/or a compound of Formula (III), or a pharmaceutically acceptablesalt of the foregoing) can be used to inhibit the hendravirus polymerasecomplex and/or nipahvirus polymerase complex.

In some embodiments, an effective amount of one or more compounds ofFormula (I), or a pharmaceutically acceptable salt thereof, one or morecompounds of Formula (II), or a pharmaceutically acceptable saltthereof, an effective amount of one or more compounds of Formula (III),or a pharmaceutically acceptable salt thereof, and/or a pharmaceuticalcomposition that includes one or more compounds described herein (e.g.,a compound of Formula (I), a compound of Formula (II) and/or a compoundof Formula (III), or a pharmaceutically acceptable salt of theforegoing) can be used to treat and/or ameliorate measles. In someembodiments, an effective amount of one or more compounds of Formula(I), or a pharmaceutically acceptable salt thereof, one or morecompounds of Formula (II), or a pharmaceutically acceptable saltthereof, an effective amount of one or more compounds of Formula (III),or a pharmaceutically acceptable salt thereof, and/or a pharmaceuticalcomposition that includes one or more compounds described herein (e.g.,a compound of Formula (I) a compound of Formula (II) and/or a compoundof Formula (III), or a pharmaceutically acceptable salt of theforegoing) can be used to prevent measles. In some embodiments, aneffective amount of one or more compounds of Formula (I), or apharmaceutically acceptable salt thereof, one or more compounds ofFormula (II), or a pharmaceutically acceptable salt thereof, aneffective amount of one or more compounds of Formula (III), or apharmaceutically acceptable salt thereof, and/or a pharmaceuticalcomposition that includes one or more compounds described herein (e.g.,a compound of Formula (I), a compound of Formula (II) and/or a compoundof Formula (III), or a pharmaceutically acceptable salt of theforegoing) can be used to inhibit the replication of a measles virus. Insome embodiments, an effective amount of one or more compounds ofFormula (I), or a pharmaceutically acceptable salt thereof, one or morecompounds of Formula (II), or a pharmaceutically acceptable saltthereof, an effective amount of one or more compounds of Formula (III),or a pharmaceutically acceptable salt thereof, and/or a pharmaceuticalcomposition that includes one or more compounds described herein (e.g.,a compound of Formula (I), a compound of Formula (II) and/or a compoundof Formula (III), or a pharmaceutically acceptable salt of theforegoing) can be used to inhibit the measles polymerase complex.

In some embodiments, an effective amount of one or more compounds ofFormula (I), or a pharmaceutically acceptable salt thereof, one or morecompounds of Formula (II), or a pharmaceutically acceptable saltthereof, an effective amount of one or more compounds of Formula (III),or a pharmaceutically acceptable salt thereof, and/or a pharmaceuticalcomposition that includes one or more compounds described herein (e.g.,a compound of Formula (I), a compound of Formula (II) and/or a compoundof Formula (III), or a pharmaceutically acceptable salt of theforegoing) can be used to treat and/or ameliorate mumps. In someembodiments, an effective amount of one or more compounds of Formula(I), or a pharmaceutically acceptable salt thereof, one or morecompounds of Formula (II), or a pharmaceutically acceptable saltthereof, an effective amount of one or more compounds of Formula (III),or a pharmaceutically acceptable salt thereof, and/or a pharmaceuticalcomposition that includes one or more compounds described herein (e.g.,a compound of Formula (I) a compound of Formula (II) and/or a compoundof Formula (III), or a pharmaceutically acceptable salt of theforegoing) can be used to prevent mumps. In some embodiments, aneffective amount of one or more compounds of Formula (I), or apharmaceutically acceptable salt thereof, one or more compounds ofFormula (II), or a pharmaceutically acceptable salt thereof, aneffective amount of one or more compounds of Formula (III), or apharmaceutically acceptable salt thereof, and/or a pharmaceuticalcomposition that includes one or more compounds described herein (e.g.,a compound of Formula (I), a compound of Formula (II) and/or a compoundof Formula (III), or a pharmaceutically acceptable salt of theforegoing) can be used to inhibit the replication of a mumps virus. Insome embodiments, an effective amount of one or more compounds ofFormula (I), or a pharmaceutically acceptable salt thereof, one or morecompounds of Formula (II), or a pharmaceutically acceptable saltthereof, an effective amount of one or more compounds of Formula (III),or a pharmaceutically acceptable salt thereof, and/or a pharmaceuticalcomposition that includes one or more compounds described herein (e.g.,a compound of Formula (I), a compound of Formula (II) and/or a compoundof Formula (III), or a pharmaceutically acceptable salt of theforegoing) can be used to inhibit the mumps polymerase complex.

In some embodiments, an effective amount of one or more compounds ofFormula (I), or a pharmaceutically acceptable salt thereof, one or morecompounds of Formula (II), or a pharmaceutically acceptable saltthereof, an effective amount of one or more compounds of Formula (III),or a pharmaceutically acceptable salt thereof, and/or a pharmaceuticalcomposition that includes one or more compounds described herein (e.g.,a compound of Formula (I), a compound of Formula (II) and/or a compoundof Formula (III), or a pharmaceutically acceptable salt of theforegoing) can be used to treat and/or ameliorate a sendai viralinfection. In some embodiments, an effective amount of one or morecompounds of Formula (I), or a pharmaceutically acceptable salt thereof,one or more compounds of Formula (II), or a pharmaceutically acceptablesalt thereof, an effective amount of one or more compounds of Formula(III), or a pharmaceutically acceptable salt thereof, and/or apharmaceutical composition that includes one or more compounds describedherein (e.g., a compound of Formula (I) a compound of Formula (II)and/or a compound of Formula (III), or a pharmaceutically acceptablesalt of the foregoing) can be used to prevent a sendai viral infection.In some embodiments, an effective amount of one or more compounds ofFormula (I), or a pharmaceutically acceptable salt thereof, one or morecompounds of Formula (II), or a pharmaceutically acceptable saltthereof, an effective amount of one or more compounds of Formula (III),or a pharmaceutically acceptable salt thereof, and/or a pharmaceuticalcomposition that includes one or more compounds described herein (e.g.,a compound of Formula (I), a compound of Formula (II) and/or a compoundof Formula (III), or a pharmaceutically acceptable salt of theforegoing) can be used to inhibit the replication of a sendai virus. Insome embodiments, an effective amount of one or more compounds ofFormula (I), or a pharmaceutically acceptable salt thereof, one or morecompounds of Formula (II), or a pharmaceutically acceptable saltthereof, an effective amount of one or more compounds of Formula (III),or a pharmaceutically acceptable salt thereof, and/or a pharmaceuticalcomposition that includes one or more compounds described herein (e.g.,a compound of Formula (I), a compound of Formula (II) and/or a compoundof Formula (III), or a pharmaceutically acceptable salt of theforegoing) can be used to inhibit the sendai virus polymerase complex.

In some embodiments, an effective amount of one or more compounds ofFormula (I), or a pharmaceutically acceptable salt thereof, one or morecompounds of Formula (II), or a pharmaceutically acceptable saltthereof, an effective amount of one or more compounds of Formula (III),or a pharmaceutically acceptable salt thereof, and/or a pharmaceuticalcomposition that includes one or more compounds described herein (e.g.,a compound of Formula (I), a compound of Formula (II) and/or a compoundof Formula (III), or a pharmaceutically acceptable salt of theforegoing) can be used to treat and/or ameliorate a HPIV-1 infectionand/or HPIV-3 infection. In some embodiments, an effective amount of oneor more compounds of Formula (I), or a pharmaceutically acceptable saltthereof, one or more compounds of Formula (II), or a pharmaceuticallyacceptable salt thereof, an effective amount of one or more compounds ofFormula (III), or a pharmaceutically acceptable salt thereof, and/or apharmaceutical composition that includes one or more compounds describedherein (e.g., a compound of Formula (I) a compound of Formula (II)and/or a compound of Formula (III), or a pharmaceutically acceptablesalt of the foregoing) can be used to prevent a HPIV-1 infection and/orHPIV-3 infection. In some embodiments, an effective amount of one ormore compounds of Formula (I), or a pharmaceutically acceptable saltthereof, one or more compounds of Formula (II), or a pharmaceuticallyacceptable salt thereof, an effective amount of one or more compounds ofFormula (III), or a pharmaceutically acceptable salt thereof, and/or apharmaceutical composition that includes one or more compounds describedherein (e.g., a compound of Formula (I), a compound of Formula (II)and/or a compound of Formula (III), or a pharmaceutically acceptablesalt of the foregoing) can be used to inhibit the replication of HPIV-1and/or HPIV-3. In some embodiments, an effective amount of one or morecompounds of Formula (I), or a pharmaceutically acceptable salt thereof,one or more compounds of Formula (II), or a pharmaceutically acceptablesalt thereof, an effective amount of one or more compounds of Formula(III), or a pharmaceutically acceptable salt thereof, and/or apharmaceutical composition that includes one or more compounds describedherein (e.g., a compound of Formula (I), a compound of Formula (II)and/or a compound of Formula (III), or a pharmaceutically acceptablesalt of the foregoing) can be used to inhibit the HPIV-1 polymerasecomplex and/or HPIV-3 polymerase complex.

In some embodiments, an effective amount of one or more compounds ofFormula (I), or a pharmaceutically acceptable salt thereof, one or morecompounds of Formula (II), or a pharmaceutically acceptable saltthereof, an effective amount of one or more compounds of Formula (III),or a pharmaceutically acceptable salt thereof, and/or a pharmaceuticalcomposition that includes one or more compounds described herein (e.g.,a compound of Formula (I), a compound of Formula (II) and/or a compoundof Formula (III), or a pharmaceutically acceptable salt of theforegoing) can be used to treat and/or ameliorate a HPIV-2 infectionand/or HPIV-4 infection. In some embodiments, an effective amount of oneor more compounds of Formula (I), or a pharmaceutically acceptable saltthereof, one or more compounds of Formula (II), or a pharmaceuticallyacceptable salt thereof, an effective amount of one or more compounds ofFormula (III), or a pharmaceutically acceptable salt thereof, and/or apharmaceutical composition that includes one or more compounds describedherein (e.g., a compound of Formula (I) a compound of Formula (II)and/or a compound of Formula (III), or a pharmaceutically acceptablesalt of the foregoing) can be used to prevent a HPIV-2 infection and/orHPIV-4 infection. In some embodiments, an effective amount of one ormore compounds of Formula (I), or a pharmaceutically acceptable saltthereof, one or more compounds of Formula (II), or a pharmaceuticallyacceptable salt thereof, an effective amount of one or more compounds ofFormula (III), or a pharmaceutically acceptable salt thereof, and/or apharmaceutical composition that includes one or more compounds describedherein (e.g., a compound of Formula (I), a compound of Formula (II)and/or a compound of Formula (III), or a pharmaceutically acceptablesalt of the foregoing) can be used to inhibit the replication of HPIV-2and/or HPIV-4. In some embodiments, an effective amount of one or morecompounds of Formula (I), or a pharmaceutically acceptable salt thereof,one or more compounds of Formula (II), or a pharmaceutically acceptablesalt thereof, an effective amount of one or more compounds of Formula(III), or a pharmaceutically acceptable salt thereof, and/or apharmaceutical composition that includes one or more compounds describedherein (e.g., a compound of Formula (I), a compound of Formula (II)and/or a compound of Formula (III), or a pharmaceutically acceptablesalt of the foregoing) can be used to inhibit the HPIV-2 polymerasecomplex and/or HPIV-4 polymerase complex.

In some embodiments, an effective amount of one or more compounds ofFormula (I), or a pharmaceutically acceptable salt thereof, one or morecompounds of Formula (II), or a pharmaceutically acceptable saltthereof, an effective amount of one or more compounds of Formula (III),or a pharmaceutically acceptable salt thereof, and/or a pharmaceuticalcomposition that includes one or more compounds described herein (e.g.,a compound of Formula (I), a compound of Formula (II) and/or a compoundof Formula (III), or a pharmaceutically acceptable salt of theforegoing) can be used to treat and/or ameliorate a humanmetapneumoviral infection. In some embodiments, an effective amount ofone or more compounds of Formula (I), or a pharmaceutically acceptablesalt thereof, one or more compounds of Formula (II), or apharmaceutically acceptable salt thereof, an effective amount of one ormore compounds of Formula (III), or a pharmaceutically acceptable saltthereof, and/or a pharmaceutical composition that includes one or morecompounds described herein (e.g., a compound of Formula (I) a compoundof Formula (II) and/or a compound of Formula (III), or apharmaceutically acceptable salt of the foregoing) can be used toprevent a human metapneumoviral infection. In some embodiments, aneffective amount of one or more compounds of Formula (I), or apharmaceutically acceptable salt thereof, one or more compounds ofFormula (II), or a pharmaceutically acceptable salt thereof, aneffective amount of one or more compounds of Formula (III), or apharmaceutically acceptable salt thereof, and/or a pharmaceuticalcomposition that includes one or more compounds described herein (e.g.,a compound of Formula (I), a compound of Formula (II) and/or a compoundof Formula (III), or a pharmaceutically acceptable salt of theforegoing) can be used to inhibit the replication of a humanmetapneumovirus. In some embodiments, an effective amount of one or morecompounds of Formula (I), or a pharmaceutically acceptable salt thereof,one or more compounds of Formula (II), or a pharmaceutically acceptablesalt thereof, an effective amount of one or more compounds of Formula(III), or a pharmaceutically acceptable salt thereof, and/or apharmaceutical composition that includes one or more compounds describedherein (e.g., a compound of Formula (I), a compound of Formula (II)and/or a compound of Formula (III), or a pharmaceutically acceptablesalt of the foregoing) can be used to inhibit the human metapneumoviruspolymerase complex.

In some embodiments, an effective amount of one or more compounds ofFormula (I), or a pharmaceutically acceptable salt thereof, one or morecompounds of Formula (II), or a pharmaceutically acceptable saltthereof, an effective amount of one or more compounds of Formula (III),or a pharmaceutically acceptable salt thereof, and/or a pharmaceuticalcomposition that includes one or more compounds described herein (e.g.,a compound of Formula (I), a compound of Formula (II) and/or a compoundof Formula (III), or a pharmaceutically acceptable salt of theforegoing) can be used treat and/or ameliorate an upper respiratoryviral infection caused by a virus selected from a henipavirus, amorbillivirus, a respirovirus, a rubulavirus, a pneumovirus, ametapneumovirus and influenza virus. In some embodiments, an effectiveamount of one or more compounds of Formula (I), or a pharmaceuticallyacceptable salt thereof, one or more compounds of Formula (II), or apharmaceutically acceptable salt thereof, an effective amount of one ormore compounds of Formula (III), or a pharmaceutically acceptable saltthereof, and/or a pharmaceutical composition that includes one or morecompounds described herein (e.g., a compound of Formula (I), a compoundof Formula (II) and/or a compound of Formula (III), or apharmaceutically acceptable salt of the foregoing) can be used treatand/or ameliorate a lower respiratory viral infection caused by a virusselected from a henipavirus, a morbillivirus, a respirovirus, arubulavirus, a pneumovirus, a metapneumovirus and influenza virus. Insome embodiments, an effective amount of one or more compounds ofFormula (I), or a pharmaceutically acceptable salt thereof, one or morecompounds of Formula (II), or a pharmaceutically acceptable saltthereof, an effective amount of one or more compounds of Formula (III),or a pharmaceutically acceptable salt thereof, and/or a pharmaceuticalcomposition that includes one or more compounds described herein (e.g.,a compound of Formula (I) a compound of Formula (II) and/or a compoundof Formula (III), or a pharmaceutically acceptable salt of theforegoing) can be used treat and/or ameliorate one or more symptoms ofan infection caused by a virus selected from a henipavirus, amorbillivirus, a respirovirus, a rubulavirus, a pneumovirus, ametapneumovirus and influenza virus (such as those described herein).

In some embodiments, an effective amount of one or more compounds ofFormula (I), or a pharmaceutically acceptable salt thereof, one or morecompounds of Formula (II), or a pharmaceutically acceptable saltthereof, an effective amount of one or more compounds of Formula (III),or a pharmaceutically acceptable salt thereof, and/or a pharmaceuticalcomposition that includes one or more compounds described herein (e.g.,a compound of Formula (I), a compound of Formula (II) and/or a compoundof Formula (III), or a pharmaceutically acceptable salt of theforegoing) can be used treat and/or ameliorate an upper respiratoryviral infection caused by RSV infection, measles, mumps, parainfluenzainfection, metapneumovirus and/or influenza infection. In someembodiments, an effective amount of one or more compounds of Formula(I), or a pharmaceutically acceptable salt thereof, one or morecompounds of Formula (II), or a pharmaceutically acceptable saltthereof, an effective amount of one or more compounds of Formula (III),or a pharmaceutically acceptable salt thereof, and/or a pharmaceuticalcomposition that includes one or more compounds described herein (e.g.,a compound of Formula (I), a compound of Formula (II) and/or a compoundof Formula (III), or a pharmaceutically acceptable salt of theforegoing) can be used treat and/or ameliorate a lower respiratory viralinfection caused by RSV infection, measles, mumps, parainfluenzainfection, metapneumovirus and/or influenza infection. In someembodiments, an effective amount of one or more compounds of Formula(I), or a pharmaceutically acceptable salt thereof, one or morecompounds of Formula (II), or a pharmaceutically acceptable saltthereof, an effective amount of one or more compounds of Formula (III),or a pharmaceutically acceptable salt thereof, and/or a pharmaceuticalcomposition that includes one or more compounds described herein (e.g.,a compound of Formula (I) a compound of Formula (II) and/or a compoundof Formula (III), or a pharmaceutically acceptable salt of theforegoing) can be used treat and/or ameliorate one or more symptoms ofan infection caused by RSV infection, measles, mumps, parainfluenzainfection, metapneumovirus and/or influenza infection (such as thosedescribed herein).

In some embodiments, an effective amount of one or more compounds ofFormula (I), or a pharmaceutically acceptable salt thereof, one or morecompounds of Formula (II), or a pharmaceutically acceptable saltthereof, an effective amount of one or more compounds of Formula (III),or a pharmaceutically acceptable salt thereof, and/or a pharmaceuticalcomposition that includes one or more compounds described herein (e.g.,a compound of Formula (I), a compound of Formula (II) and/or a compoundof Formula (III), or a pharmaceutically acceptable salt of theforegoing) can be used treat and/or ameliorate bronchiolitis and/ortracheobronchitis due to a RSV infection, influenza infection and/orhuman parainfluenza virus 3 (HPIV-3) infection. In some embodiments, aneffective amount of one or more compounds of Formula (I), or apharmaceutically acceptable salt thereof, one or more compounds ofFormula (II), or a pharmaceutically acceptable salt thereof, aneffective amount of one or more compounds of Formula (III), or apharmaceutically acceptable salt thereof, and/or a pharmaceuticalcomposition that includes one or more compounds described herein (e.g.,a compound of Formula (I), a compound of Formula (II) and/or a compoundof Formula (III), or a pharmaceutically acceptable salt of theforegoing) can be used treat and/or ameliorate pneumonia due to a RSVinfection, influenza infection and/or human parainfluenza virus 3(HPIV-3) infection. In some embodiments, an effective amount of one ormore compounds of Formula (I), or a pharmaceutically acceptable saltthereof, one or more compounds of Formula (II), or a pharmaceuticallyacceptable salt thereof, an effective amount of one or more compounds ofFormula (III), or a pharmaceutically acceptable salt thereof, and/or apharmaceutical composition that includes one or more compounds describedherein (e.g., a compound of Formula (I), a compound of Formula (II)and/or a compound of Formula (III), or a pharmaceutically acceptablesalt of the foregoing) can be used treat and/or ameliorate croup due toa RSV infection, influenza infection and/or human parainfluenza virus 1(HPIV-1) infection.

In some embodiments, an effective amount of one or more compounds ofFormula (I), or a pharmaceutically acceptable salt thereof, one or morecompounds of Formula (II), or a pharmaceutically acceptable saltthereof, an effective amount of one or more compounds of Formula (III),or a pharmaceutically acceptable salt thereof, and/or a pharmaceuticalcomposition that includes one or more compounds described herein (e.g.,a compound of Formula (I), a compound of Formula (II) and/or a compoundof Formula (III), or a pharmaceutically acceptable salt of theforegoing) can be used treat and/or ameliorate a fever, cough, runnynose, red eyes, a generalized rash, pneumonia, an ear infection and/orbronchitis due to measles. In some embodiments, an effective amount ofone or more compounds of Formula (I), or a pharmaceutically acceptablesalt thereof, one or more compounds of Formula (II), or apharmaceutically acceptable salt thereof, an effective amount of one ormore compounds of Formula (III), or a pharmaceutically acceptable saltthereof, and/or a pharmaceutical composition that includes one or morecompounds described herein (e.g., a compound of Formula (I), a compoundof Formula (II) and/or a compound of Formula (III), or apharmaceutically acceptable salt of the foregoing) can be used treatand/or ameliorate swelling of the salivary glands, fever, loss ofappetite and/or fatigue due to mumps.

In some embodiments, an effective amount of one or more compounds ofFormula (I), or a pharmaceutically acceptable salt thereof, one or morecompounds of Formula (II), or a pharmaceutically acceptable saltthereof, an effective amount of one or more compounds of Formula (III),or a pharmaceutically acceptable salt thereof, and/or a pharmaceuticalcomposition that includes one or more compounds described herein (e.g.,a compound of Formula (I), a compound of Formula (II) and/or a compoundof Formula (III), or a pharmaceutically acceptable salt of theforegoing) can be used to prevent an influenza viral infection. In someembodiments, the influenza viral infection can be an influenza A viralinfection. In other embodiments, the influenza viral infection can be aninfluenza B viral infection. In still other embodiments, the influenzaviral infection can be an influenza C viral infection. In someembodiments, one or more compounds of Formula (I), or a pharmaceuticallyacceptable salt thereof, one or more compounds of Formula (II), or apharmaceutically acceptable salt thereof, and/or one or more compoundsof Formula (III), or a pharmaceutically acceptable salt thereof, can beused to treat and/or ameliorate one or more subtypes of influenza. Forexample, one or more compounds of Formula (I), or a pharmaceuticallyacceptable salt thereof, one or more compounds of Formula (II), or apharmaceutically acceptable salt thereof, and/or one or more compoundsof Formula (III), or a pharmaceutically acceptable salt thereof, can beused to treat H1N1 and/or H3N2.

In some embodiments, an effective amount of one or more compounds ofFormula (I), or a pharmaceutically acceptable salt thereof, one or morecompounds of Formula (II), or a pharmaceutically acceptable saltthereof, an effective amount of one or more compounds of Formula (III),or a pharmaceutically acceptable salt thereof, and/or a pharmaceuticalcomposition that includes one or more compounds described herein (e.g.,a compound of Formula (I), a compound of Formula (II) and/or a compoundof Formula (III), or a pharmaceutically acceptable salt of theforegoing) can be used to prevent a human parainfluenza viral infection.In some embodiments, the human parainfluenza viral infection can be ahuman parainfluenza virus 1 (HPIV-1). In other embodiments, the humanparainfluenza viral infection can be a human parainfluenza virus 2(HPIV-2). In other embodiments, the human parainfluenza viral infectioncan be a human parainfluenza virus 3 (HPIV-3). In other embodiments, thehuman parainfluenza viral infection can be a human parainfluenza virus 4(HPIV-4). In some embodiments, one or more compounds of Formula (I), ora pharmaceutically acceptable salt thereof, one or more compounds ofFormula (II), or a pharmaceutically acceptable salt thereof, and/or oneor more compounds of Formula (III), or a pharmaceutically acceptablesalt thereof, can be used to treat and/or ameliorate one or moresubtypes of human parainfluenza virus. For example, one or morecompounds of Formula (I), or a pharmaceutically acceptable salt thereof,one or more compounds of Formula (II), or a pharmaceutically acceptablesalt thereof, and/or one or more compounds of Formula (III), or apharmaceutically acceptable salt thereof, can be used to treat HPIV-1and/or HPIV-3.

The one or more compounds of Formula (I) or a pharmaceuticallyacceptable salt thereof, one or more compounds of Formula (II), or apharmaceutically acceptable salt thereof, and/or one or more compoundsof Formula (III), or a pharmaceutically acceptable salt thereof, thatcan be used to treat, ameliorate and/or prevent a paramyxovirus and/oror an orthomyxovirus viral infection can be a compound of Formula (I),or pharmaceutically acceptable salt thereof, and/or a compound ofFormula (II), or a pharmaceutically acceptable salt thereof, and/or acompound of Formula (III), or a pharmaceutically acceptable saltthereof, provided in any of the embodiments described in paragraphs[0085]-[0171].

As used herein, the terms “prevent” and “preventing,” mean a subjectdoes not develop an infection because the subject has an immunityagainst the infection, or if a subject becomes infected, the severity ofthe disease is less compared to the severity of the disease if thesubject has not been administered/received the compound. Examples offorms of prevention include prophylactic administration to a subject whohas been or may be exposed to an infectious agent, such as aparamyxovirus (e.g., RSV) and/or an orthomyxovirus (e.g., influenza).

As used herein, the terms “treat,” “treating,” “treatment,”“therapeutic,” and “therapy” do not necessarily mean total cure orabolition of the disease or condition. Any alleviation of any undesiredsigns or symptoms of a disease or condition, to any extent can beconsidered treatment and/or therapy. Furthermore, treatment may includeacts that may worsen the subject's overall feeling of well-being orappearance.

The terms “therapeutically effective amount” and “effective amount” areused to indicate an amount of an active compound, or pharmaceuticalagent, that elicits the biological or medicinal response indicated. Forexample, a therapeutically effective amount of compound can be theamount needed to prevent, alleviate or ameliorate symptoms of disease orprolong the survival of the subject being treated This response mayoccur in a tissue, system, animal or human and includes alleviation ofthe signs or symptoms of the disease being treated. Determination of aneffective amount is well within the capability of those skilled in theart, in view of the disclosure provided herein. The therapeuticallyeffective amount of the compounds disclosed herein required as a dosewill depend on the route of administration, the type of animal,including human, being treated, and the physical characteristics of thespecific animal under consideration. The dose can be tailored to achievea desired effect, but will depend on such factors as weight, diet,concurrent medication and other factors which those skilled in themedical arts will recognize.

Various indicators for determining the effectiveness of a method fortreating a viral infection, such as a paramyxovirus and/or anorthomyxovirus infection, are known to those skilled in the art. Exampleof suitable indicators include, but are not limited to, a reduction inviral load, a reduction in viral replication, a reduction in time toseroconversion (virus undetectable in patient serum), a reduction ofmorbidity or mortality in clinical outcomes, and/or other indicator ofdisease response.

In some embodiments, an effective amount of a compound of Formulae (I),(II) and/or (III), or a pharmaceutically acceptable salt of theforegoing, is an amount that is effective to reduce viral titers toundetectable levels, for example, to about 1000 to about 5000, to about500 to about 1000, or to about 100 to about 500 genome copies/mL serum.In some embodiments, an effective amount of a compound of Formulae (I),(II) and/or (III), or a pharmaceutically acceptable salt of theforegoing, is an amount that is effective to reduce viral load comparedto the viral load before administration of the compound of Formulae (I),(II) and/or (III), or a pharmaceutically acceptable salt of theforegoing. For example, wherein the viral load is measure beforeadministration of the compound of Formulae (I), (II) and/or (III), or apharmaceutically acceptable salt of the foregoing, and again aftercompletion of the treatment regime with the compound of Formulae (I),(II) and/or (III), or a pharmaceutically acceptable salt of theforegoing (for example, 1 week after completion). In some embodiments,an effective amount of a compound of Formulae (I), (II) and/or (III), ora pharmaceutically acceptable salt of the foregoing, can be an amountthat is effective to reduce viral load to lower than about 100 genomecopies/mL serum. In some embodiments, an effective amount of a compoundof Formulae (I), (II) and/or (III), or a pharmaceutically acceptablesalt of the foregoing, is an amount that is effective to achieve areduction in viral titer in the serum of the subject in the range ofabout 1.5-log to about a 2.5-log reduction, about a 3-log to about a4-log reduction, or a greater than about 5-log reduction compared to theviral load before administration of the compound of Formulae (I), (II)and/or (III), or a pharmaceutically acceptable salt of the foregoing.For example, wherein the viral load is measure before administration ofthe compound of Formulae (I), (II) and/or (III), or a pharmaceuticallyacceptable salt of the foregoing, and again after completion of thetreatment regime with the compound of Formulae (I), (II) and/or (III),or a pharmaceutically acceptable salt of the foregoing (for example, 1week after completion).

In some embodiments, a compound of Formulae (I), (II) and/or (III), or apharmaceutically acceptable salt of the foregoing, can result in atleast a 1, 2, 3, 4, 5, 10, 15, 20, 25, 50, 75, 100-fold or morereduction in the replication of a paramyxovirus and/or an orthomyxovirusrelative to pre-treatment levels in a subject, as determined aftercompletion of the treatment regime (for example, 1 week aftercompletion). In some embodiments, a compound of Formulae (I), (II)and/or (III), or a pharmaceutically acceptable salt of the foregoing,can result in a reduction of the replication of a paramyxovirus and/oran orthomyxovirus relative to pre-treatment levels in the range of about2 to about 5 fold, about 10 to about 20 fold, about 15 to about 40 fold,or about 50 to about 100 fold. In some embodiments, a compound ofFormulae (I), (II) and/or (III), or a pharmaceutically acceptable saltof the foregoing, can result in a reduction of paramyxovirus replicationin the range of 1 to 1.5 log, 1.5 log to 2 log, 2 log to 2.5 log, 2.5 to3 log, 3 log to 3.5 log or 3.5 to 4 log more reduction of paramyxovirusreplication compared to the reduction of paramyxovirus reductionachieved by ribavirin (Virazole®), or may achieve the same reduction asthat of ribavirin (Virazole®) therapy in a shorter period of time, forexample, in one week, two weeks, one month, two months, or three months,as compared to the reduction achieved after six months of ribavirin(Virazole®) therapy. In some embodiments, a compound of Formulae (I),(II) and/or (III), or a pharmaceutically acceptable salt of theforegoing, can result in a reduction of orthomyxovirus replication inthe range of 1 to 1.5 log, 1.5 log to 2 log, 2 log to 2.5 log, 2.5 to 3log, 3 log to 3.5 log or 3.5 to 4 log more reduction of orthomyxovirusreplication compared to the reduction of orthomyxovirus reductionachieved by oseltamivir (Tamiflu®), or may achieve the same reduction asthat of oseltamivir (Tamiflu®) therapy in a shorter period of time, forexample, in one week, two weeks, one month, two months, or three months,as compared to the reduction achieved after six months of oseltamivir(Tamiflu®) therapy.

In some embodiments, an effective amount of a compound of Formula (I), acompound of Formula (II) and/or a compound of Formula (III), or apharmaceutically acceptable salt of the foregoing, is an amount that iseffective to achieve a sustained viral response, for example,non-detectable or substantially non-detectable paramyxovirus and/ororthomyxovirus RNA (e.g., less than about 500, less than about 400, lessthan about 200, or less than about 100 genome copies per milliliterserum) is found in the subject's serum for a period of at least aboutone week, two weeks, one month, at least about two months, at leastabout three months, at least about four months, at least about fivemonths, or at least about six months following cessation of therapy.

After a period of time, infectious agents can develop resistance to oneor more therapeutic agents. The term “resistance” as used herein refersto a viral strain displaying a delayed, lessened and/or null response toa therapeutic agent(s). For example, after treatment with an antiviralagent, the viral load of a subject infected with a resistant virus maybe reduced to a lesser degree compared to the amount in viral loadreduction exhibited by a subject infected with a non-resistant strain.In some embodiments, a compound of Formula (I), a compound of Formula(II) and/or a compound of Formula (III), or a pharmaceuticallyacceptable salt of the foregoing, can be administered to a subjectinfected with RSV that is resistant to one or more different anti-RSVagents (for example, ribavirin). In some embodiments, development ofresistant RSV strains can be delayed when subjects are treated with acompound of Formula (I), a compound of Formula (II) and/or a compound ofFormula (III), or a pharmaceutically acceptable salt of the foregoing,compared to the development of RSV strains resistant to other RSV drugs.In some embodiments, a compound of Formula (I), a compound of Formula(II) and/or a compound of Formula (III), or a pharmaceuticallyacceptable salt of the foregoing, can be administered to a subjectinfected with an influenza virus that is resistant to one or moredifferent anti-influenza agents (for example, amantadine andrimantadine). In some embodiments, development of resistant influenzastrains can be delayed when subjects are treated with a compound ofFormula (I), a compound of Formula (II) and/or a compound of Formula(III), or a pharmaceutically acceptable salt of the foregoing, comparedto the development of influenza strains resistant to other influenzadrugs.

In some embodiments, a compound of Formula (I), a compound of Formula(II) and/or a compound of Formula (III), or a pharmaceuticallyacceptable salt of the foregoing, can decrease the percentage ofsubjects that experience complications from a RSV viral infectioncompared to the percentage of subjects that experience complicationbeing treated with ribavirin. In some embodiments, a compound of Formula(I), a compound of Formula (II) and/or a compound of Formula (III), or apharmaceutically acceptable salt of the foregoing, can decrease thepercentage of subjects that experience complications from an influenzaviral infection compared to the percentage of subjects that experiencecomplication being treated with oseltamivir. For example, the percentageof subjects being treated with a compound of Formula (I), a compound ofFormula (II) and/or a compound of Formula (III), or a pharmaceuticallyacceptable salt of the foregoing, that experience complications can be10%, 25%, 40%, 50%, 60%, 70%, 80% and 90% less compared to subjectsbeing treated with ribavirin or oseltamivir.

In some embodiments, a compound of Formula (I), a compound of Formula(II) and/or a compound of Formula (III), or a pharmaceuticallyacceptable salt of the foregoing, or a pharmaceutical composition thatincludes a compound described herein, can be used in combination withone or more additional agent(s). In some embodiments, a compound ofFormula (I), a compound of Formula (II) and/or a compound of Formula(III), or a pharmaceutically acceptable salt of the foregoing, can beused in combination with one or more agents currently used for treatingRSV. For example, the additional agent can be ribavirin, palivizumab andRSV-IGIV. For the treatment of RSV, additional agents include but arenot limited to ALN-RSV01 (Alnylam Pharmaceuticals), BMS-433771(1-cyclopropyl-3-[[1-(4-hydroxybutyl)benzimidazol-2-yl]methyl]imidazo[4,5-c]pyridin-2-one),RFI-641((4,4″-bis-{4,6-bis-[3-(bis-carbamoylmethyl-sulfamoyl)-phenylamino]-(1,3,5)triazin-2-ylamino}-biphenyl-2,2″-disulfonic-acid)),RSV604((S)-1-(2-fluorophenyl)-3-(2-oxo-5-phenyl-2,3-dihydro-1H-benzo[e][1,4]di-azepin-3-yl)-urea),MDT-637((4Z)-2-methylsulfanyl-4-[(E)-3-thiophen-2-ylprop-2-enylidene]-1,3-thiazol-5-one),BTA9881, TMC-353121 (Tibotec), MBX-300, YM-53403(N-cyclopropyl-6-[4-[(2-phenylbenzoyl)amino]benzoyl]-4,5-dihydrothieno[3,2-d][1]benzazepine-2-carboxamide), motavizumab (Medi-524, MedImmune), Medi-559,Medi-534, Medi-557, RV568 and a RSV-F Particle Vaccine (Novavax). Insome embodiments, a compound of Formula (I), a compound of Formula (II)and/or a compound of Formula (III), or a pharmaceutically acceptablesalt of the foregoing, can be used in combination with one or moreagents currently used for treating influenza. For example, theadditional agent can be amantadine, rimantadine, zanamivir andoseltamivir. For the treatment of influenza, additional agents includebut are not limited to peramivir((1S,2S,3S,4R)-3-[(1S)-1-acetamido-2-ethylbutyl]-4-(diaminomethylideneamino)-2-hydroxycyclopentane-1-carboxylicacid), laninamivir((4S,5R,6R)-5-acetamido-4-carbamimidamido-6-[(1R,2R)-3-hydroxy-2-methoxypropyl]-5,6-dihydro-4H-pyran-2-carboxylicacid), favipiravir (T-705, 6-fluoro-3-hydroxy-2-pyrazinecarboxamide),fludase (DAS181, NexBio), ADS-8902 (Adamas Pharmaceuticals), IFN-b(Synairgen), beraprost(4-[2-hydroxy-1-[(E)-3-hydroxy-4-methyloct-1-en-6-ynyl]-2,3,3a,8b-tetrahydro-1H-cyclopenta[b][1]benzofuran-5-yl]butanoicacid), Neugene® and VGX-3400X (Inovio).

In some embodiments, a compound of Formula (I), a compound of Formula(II) and/or a compound of Formula (III), or a pharmaceuticallyacceptable salt of the foregoing, can be administered with one or moreadditional agent(s) together in a single pharmaceutical composition. Insome embodiments, a compound of Formula (I), a compound of Formula (II)and/or a compound of Formula (III), or a pharmaceutically acceptablesalt of the foregoing, can be administered with one or more additionalagent(s) as two or more separate pharmaceutical compositions. Forexample, a compound of Formula (I), a compound of Formula (II) and/or acompound of Formula (III), or a pharmaceutically acceptable salt of theforegoing, can be administered in one pharmaceutical composition, and atleast one of the additional agents can be administered in a secondpharmaceutical composition. If there are at least two additional agents,one or more of the additional agents can be in a first pharmaceuticalcomposition that includes a compound of Formula (I), a compound ofFormula (II) and/or a compound of Formula (III), or a pharmaceuticallyacceptable salt of the foregoing, and at least one of the otheradditional agent(s) can be in a second pharmaceutical composition.

The order of administration of a compound of Formula (I), a compound ofFormula (II) and/or a compound of Formula (III), or a pharmaceuticallyacceptable salt of the foregoing, with one or more additional agent(s)can vary. In some embodiments, a compound of Formula (I), a compound ofFormula (II) and/or a compound of Formula (III), or a pharmaceuticallyacceptable salt of the foregoing, can be administered prior to alladditional agents. In other embodiments, a compound of Formula (I), acompound of Formula (II) and/or a compound of Formula (III), or apharmaceutically acceptable salt of the foregoing, can be administeredprior to at least one additional agent. In still other embodiments, acompound of Formula (I), a compound of Formula (II) and/or a compound ofFormula (III), or a pharmaceutically acceptable salt of the foregoing,can be administered concomitantly with one or more additional agent(s).In yet still other embodiments, a compound of Formula (I), a compound ofFormula (II) and/or a compound of Formula (III), or a pharmaceuticallyacceptable salt of the foregoing, can be administered subsequent to theadministration of at least one additional agent. In some embodiments, acompound of Formula (I), a compound of Formula (II) and/or a compound ofFormula (III), or a pharmaceutically acceptable salt of the foregoing,can be administered subsequent to the administration of all additionalagents.

A potential advantage of utilizing a compound of Formula (I), a compoundof Formula (II) and/or a compound of Formula (III), or apharmaceutically acceptable salt of the foregoing, in combination withone or more additional agent(s) described in paragraph [0222], includingpharmaceutically acceptable salts and prodrugs thereof, may be areduction in the required amount(s) of one or more compounds ofparagraph [0222] (including pharmaceutically acceptable salts andprodrugs thereof) that is effective in treating a disease conditiondisclosed herein (for example, RSV and/or influenza), as compared to theamount required to achieve same therapeutic result when one or morecompounds described in paragraph [0222], including pharmaceuticallyacceptable salts and prodrugs thereof, are administered without acompound of Formula (I), a compound of Formula (II) and/or a compound ofFormula (III), or a pharmaceutically acceptable salt the foregoing. Forexample, the amount of a compound described in paragraph [0222],including a pharmaceutically acceptable salt and prodrug thereof, can beless compared to the amount of the compound described in paragraph[0222], including a pharmaceutically acceptable salt and prodrugthereof, needed to achieve the same viral load reduction whenadministered as a monotherapy. Another potential advantage of utilizinga compound of Formula (I), a compound of Formula (II) and/or a compoundof Formula (III), or a pharmaceutically acceptable salt of theforegoing, in combination with one or more additional agent(s) describedin paragraph [0222], including pharmaceutically acceptable salts andprodrugs thereof, is that the use of two or more compounds havingdifferent mechanism of actions can create a higher barrier to thedevelopment of resistant viral strains compared to the barrier when acompound is administered as monotherapy.

Additional advantages of utilizing a compound of Formula (I), a compoundof Formula (II) and/or a compound of Formula (III), or apharmaceutically acceptable salt the foregoing, in combination with oneor more additional agent(s) described in paragraph [0222], includingpharmaceutically acceptable salts and prodrugs thereof, may includelittle to no cross resistance between a compound of Formula (I), acompound of Formula (II) and/or a compound of Formula (III), or apharmaceutically acceptable salt the foregoing, and one or moreadditional agent(s) described in paragraph [0222] (includingpharmaceutically acceptable salts and prodrugs thereof); differentroutes for elimination of a compound of Formula (I), a compound ofFormula (II) and/or a compound of Formula (III), or a pharmaceuticallyacceptable salt the foregoing, and one or more additional agent(s)described in paragraph [0222] (including pharmaceutically acceptablesalts and prodrugs thereof); little to no overlapping toxicities betweena compound of Formula (I), a compound of Formula (II) and/or a compoundof Formula (III), or a pharmaceutically acceptable salt the foregoing,and one or more additional agent(s) described in paragraph [0222](including pharmaceutically acceptable salts and prodrugs thereof);little to no significant effects on cytochrome P450; and/or little to nopharmacokinetic interactions between a compound of Formula (I), or apharmaceutically acceptable salt thereof, and one or more additionalagent(s) described in paragraph [0222] (including pharmaceuticallyacceptable salts and prodrugs thereof).

As will be readily apparent to one skilled in the art, the useful invivo dosage to be administered and the particular mode of administrationwill vary depending upon the age, weight, the severity of theaffliction, and mammalian species treated, the particular compoundsemployed, and the specific use for which these compounds are employed.The determination of effective dosage levels, that is the dosage levelsnecessary to achieve the desired result, can be accomplished by oneskilled in the art using routine methods, for example, human clinicaltrials and in vitro studies.

The dosage may range broadly, depending upon the desired effects and thetherapeutic indication. Alternatively dosages may be based andcalculated upon the surface area of the patient, as understood by thoseof skill in the art. Although the exact dosage will be determined on adrug-by-drug basis, in most cases, some generalizations regarding thedosage can be made. The daily dosage regimen for an adult human patientmay be, for example, an oral dose of between 0.01 mg and 3000 mg of eachactive ingredient, preferably between 1 mg and 700 mg, e.g. 5 to 200 mg.The dosage may be a single one or a series of two or more given in thecourse of one or more days, as is needed by the subject. In someembodiments, the compounds will be administered for a period ofcontinuous therapy, for example for a week or more, or for months oryears.

In instances where human dosages for compounds have been established forat least some condition, those same dosages may be used, or dosages thatare between about 0.1% and 500%, more preferably between about 25% and250% of the established human dosage. Where no human dosage isestablished, as will be the case for newly-discovered pharmaceuticalcompositions, a suitable human dosage can be inferred from ED₅₀ or ID₅₀values, or other appropriate values derived from in vitro or in vivostudies, as qualified by toxicity studies and efficacy studies inanimals.

In cases of administration of a pharmaceutically acceptable salt,dosages may be calculated as the free base. As will be understood bythose of skill in the art, in certain situations it may be necessary toadminister the compounds disclosed herein in amounts that exceed, oreven far exceed, the above-stated, preferred dosage range in order toeffectively and aggressively treat particularly aggressive diseases orinfections.

Dosage amount and interval may be adjusted individually to provideplasma levels of the active moiety which are sufficient to maintain themodulating effects, or minimal effective concentration (MEC). The MECwill vary for each compound but can be estimated from in vitro data.Dosages necessary to achieve the MEC will depend on individualcharacteristics and route of administration. However, HPLC assays orbioassays can be used to determine plasma concentrations. Dosageintervals can also be determined using MEC value. Compositions should beadministered using a regimen which maintains plasma levels above the MECfor 10-90% of the time, preferably between 30-90% and most preferablybetween 50-90%. In cases of local administration or selective uptake,the effective local concentration of the drug may not be related toplasma concentration.

It should be noted that the attending physician would know how to andwhen to terminate, interrupt, or adjust administration due to toxicityor organ dysfunctions. Conversely, the attending physician would alsoknow to adjust treatment to higher levels if the clinical response werenot adequate (precluding toxicity). The magnitude of an administrateddose in the management of the disorder of interest will vary with theseverity of the condition to be treated and to the route ofadministration. The severity of the condition may, for example, beevaluated, in part, by standard prognostic evaluation methods. Further,the dose and perhaps dose frequency, will also vary according to theage, body weight, and response of the individual patient. A programcomparable to that discussed above may be used in veterinary medicine.

Compounds disclosed herein can be evaluated for efficacy and toxicityusing known methods. For example, the toxicology of a particularcompound, or of a subset of the compounds, sharing certain chemicalmoieties, may be established by determining in vitro toxicity towards acell line, such as a mammalian, and preferably human, cell line. Theresults of such studies are often predictive of toxicity in animals,such as mammals, or more specifically, humans. Alternatively, thetoxicity of particular compounds in an animal model, such as mice, rats,rabbits, or monkeys, may be determined using known methods. The efficacyof a particular compound may be established using several recognizedmethods, such as in vitro methods, animal models, or human clinicaltrials. When selecting a model to determine efficacy, the skilledartisan can be guided by the state of the art to choose an appropriatemodel, dose, route of administration and/or regime.

EXAMPLES

Additional embodiments are disclosed in further detail in the followingexamples, which are not in any way intended to limit the scope of theclaims.

Example 1 Preparation of Compound (1a)

Preparation of (P1-2):

To an ice cooled solution of P1-1 (10.0 g, 40.8 mmol) in dry pyridine(100 mL) was added TBSCl in pyridine (1M, 53 mL) dropwise at roomtemperature (R.T.). The reaction mixture was stirred at R.T. for 16hours. The reaction mixture was then quenched with water, concentratedto give a residue. The residue was separated by ethyl acetate (EA) andsaturated NaHCO₃ aq. solution. The organic phase was dried andconcentrated. The residue was purified on a silica gel column (5% MeOHin DCM) to give a crude 5′-O-TBS protected intermediate as a white solid(13.4 g, 91%). The intermediate was dissolved in anhydrous DCM (100 mL)and sym-collidine (17.9 g, 149.2 mmol), AgNO₃ (25 g, 149.2 mmol) andMMTrCl (45 g, 149.2 mmol) were added. The mixture was stirred at R.T.for 16 hours. The mixture was quenched with water, and the organic layerwas separated and concentrated. The residue purified on a silica gelcolumn (30% PE in EA) to give the crude product. The crude product wasdissolved in 1M TBAF (50 mL) in THF. The mixture was stirred at R.T. for2 hours. The solvent was removed, and the residue was purified on asilica gel column (50% PE in EA) to give P1-2 as a white solid (21.4 g,66% for three steps).

Preparation of (P1-3):

To a solution of pyridine (521 mg, 6.59 mmol) in anhydrous DMSO (5 mL)was added TFA (636 mg, 5.58 mmol) dropwise at 10° C. under nitrogen. Thereaction mixture was stirred until the solution became clear. Thesolution was then added into a mixture of P1-2 (4.0 g, 5.07 mmol) andDCC (3.86 g, 18.76 mmol) in anhydrous DMSO (18 mL) at R.T. undernitrogen. The reaction mixture was stirred at 30° C. overnight. Water(80 mL) was added into the mixture, diluted with EtOAc (100 mL) andfiltered. The filtrate was extracted with DCM (100 mL×6). The organiclayer was washed with saturated aq. NaHCO₃, dried over Na₂SO₄ andconcentrated in vacuo. The residue was purified on a silica gel columneluted with 1% MeOH in DCM to give the intermediate (3.5 g, 87.7%) as ayellow solid. The intermediate (3.5 g, 4.45 mmol) was dissolved indioxane (25 mL) and aq. HCHO (668 mg, 22.25 mmol) was added at R.T. 2NNaOH (4.5 mL, 8.9 mmol) was then added. The reaction mixture was stirredat 30° C. overnight. NaBH₄ (593 mg, 15.6 mmol) was added in by portionsat 5° C., and the mixture was stirred at R.T. for 15 min. The reactionwas quenched with water, and the mixture was extracted with EtOAc (100mL×3). The organic layer was dried over Na₂SO₄ and concentrated invacuo. The residue was purified on a silica gel column eluted with 1%MeOH in DCM to give P1-3 as a yellow solid (2.5 g, 67%). ¹H NMR (CDCl₃,400 MHz) δ 6.82-7.50 (m, 29H), 5.40 (d, J=23.2 Hz, 1H), 4.99 (d, J=7.6Hz, 1H), 4.46 (dd, J₁=6.0 Hz, J₂=54.4 Hz, 1H), 3.94 (dd, J₁=4.4 Hz,J₂=12.4 Hz, 1H), 3.78 (s, 6H), 3.42-3.69 (m, 2H), 2.71-3.05 (m, 2H),2.45 (m, 1H).

Preparation of (P1-4):

To an ice cooled solution of P1-3 (4.0 g, 4.9 mmol) in dry pyridine (20mL) was added dropwise TBSCl in pyridine (1M, 5.88 mL). The reactionmixture was stirred at R.T. for 16 hours. The reaction mixture was thenquenched with water, concentrated to give a residue. The residue wasseparated in EA and saturated aq. NaHCO₃. The organic layer wasseparated and dried, and then concentrated. The residue was purified ona silica gel column (1% MeOH in DCM) to give the intermediate as ayellow solid (3.2 g, 70%). ¹H NMR (CDCl₃, 400 MHz) δ 7.53-6.83 (m, 29H),5.51 (d, J=21.2 Hz, 1H), 4.98 (d, J=7.6 Hz, 1H), 4.67 (dd, J₁=5.6 Hz,J₂=22.4 Hz, 1H), 4.22 (dd, J₁=5.6 Hz, J₂=53.2 Hz, 1H), 4.07 (m, 1H),3.89 (m, 1H), 3.80 (s, 6H), 3.70-3.67 (m, 1H), 3.03-2.98 (m, 1H), 2.26(m, 1H), 0.93 (s, 9H), 0.10 (s, 6H).

The obtained intermediate was dissolved in anhydrous DCM (20 mL) andcollidine (360 mg, 3 mmol), and AgNO₃ (500 mg, 3 mmol) and MMTrCl (606mg, 2 mmol) were added. The mixture was stirred at R.T. for 16 hours.The reaction mixture was quenched with water, and the organic layer wasseparated and concentrated. The residue was purified on a silica gelcolumn (0.5% MeOH in DCM) to give the fully protected intermediate as ayellow solid (3.3 g, 80%). The intermediate was dissolved in 1M TBAF inTHF (5 mL) and was stirred at R.T. for 2 hours. The solution wasconcentrated, and the residue was purified on a silica gel column (1%MeOH in DCM) to give a mixture of P1-3 and P1-4, which was separated byHPLC separation (MeCN and 0.1% HCOOH in water) to give P1-4 as a whitesolid (1.5 g, 25%).

Preparation of (P1-5):

P1-4 (1.5 g, 1.22 mmol) was suspended in anhydrous DCM (50 mL), and DessMartin periodinane (1.2 g, 2.73 mmol) was added at 0° C. The reactionmixture was stirred at R.T. for 3 hours. The reaction mixture was thenquenched with saturated aq. Na₂S₂O₃ and Na₂CO₃. The organic layer wasseparated and dried, and then concentrated to give the aldehydeintermediate as a white solid.

A solution of ClCH₂PPh₃Br (2.19 g, 5.6 mmol) in anhydrous THF (40 mL)was cooled to −78° C. n-BuLi (2.5 M, 2.3 mL) was added in dropwise.After the addition, the mixture was stirred at 0° C. for 2 hours. Asolution of the aldehyde in anhydrous THF (10 mL) was then added. Themixture was stirred at R.T. for 16 hours. The reaction was quenched withsaturated NH₄Cl aq. and extracted by EA. The organic layer wasseparated, dried and concentrated. The residue was purified on a silicagel column (1% MeOH in DCM) to give the intermediate as a yellow solid(1.1 g, 73%). To a solution of the intermediate (1.1 g, 0.98 mmol) inanhydrous THF (40 mL) was added n-BuLi (2.5M, 6 mL)-78° C. dropwise. Themixture was stirred at −78° C. for 5 hours and then quenched with asaturated NH₄Cl aq. solution. The mixture was extracted with EA. Theorganic layer was separated, dried and concentrated. The residue waspurified on a silica gel column (2% MeOH in DCM) to give P1-5 as ayellow solid (910 mg, 86%).

Preparation of (1a):

P1-5 (910 mg, 0.84 mmol) was suspended in 80% CH₃COOH (50 mL), and thereaction mixture was stirred at 40° C. for 15 hours. The solvents wereevaporated, and the residue was co-evaporated with toluene to removetraces of acid and water. The residue was purified by HPLC separation(MeCN and 0.1% HCOOH in water) to give pure compound 1a as a white solid(101 mg, 45%). ¹H NMR (MeOD, 400 MHz) δ 7.90 (d, J=7.2 Hz, 1H), 6.04 (d,J=19.6 Hz, 1H), 5.87 (d, J=7.6 Hz, 1H), 5.00 (dd, J₁=5.2 Hz, J₂=53.6 Hz,1H), 4.47 (dd, J₁=5.2 Hz, J₂=22.8 Hz, 1H), 3.86 (d, J=12.4 Hz, 1H), 3.73(d, J=12.4 Hz, 1H), 3.08 (s, 1H); ESI-TOF-MS: m/z 270.09 [M+H]⁺, 539.17[2M+H]⁺.

Example 2 Preparation of Compound (2a)

To a stirred solution of compound 1a (50 mg, 0.186 mmol) in anhydrousTHF (3 mL) was added dropwise a solution of t-BuMgCl (0.37 mL, 1M inTHF) at −78° C. The mixture was then stirred at 0° C. for 30 min andre-cooled to −78° C. A solution of phenyl (isopropoxy-L-alaninyl)phosphorochloridate (104 mg, 0.4 mmol) in THF (0.5 mL) was addeddropwise. After addition, the mixture was stirred at 25° C. for 16hours. The reaction was quenched with HCOOH (80% aq.) at 0° C. Thesolvent was removed, and the residue was purified on silica gel(DCM:MeOH=50:1 to 10:1) to give compound 2a as a white solid (a mixtureof two β isomers, 8.0 mg, 7.9%). ¹H NMR (MeOD, 400 MHz) δ 7.71, 7.68(2d, J=7.6 Hz, 1H), 7.17-7.37 (m, 5H), 6.02, 6.00 (2d, J=20.4 Hz, 1H),5.90, 5.86 (2d, J=7.6 Hz, 1H), 5.03-5.18 (m, 1H), 4.91-4.99 (m, 1H),4.45-4.55 (m, 1H), 4.34-4.43 (m, 1H), 4.26-4.33 (m, 1H), 3.87-3.95 (m,1H), 3.25, 3.22 (2s, 1H), 1.29-1.34 (m, 3H), 1.20-1.22 (m, 6H). ³¹P NMR(MeOD, 162 MHz) δ 3.44, 3.27. ESI-LCMS: m/z 539.0 [M+H]⁺.

Example 3 Preparation of Compound (3a)

Preparation of (P3-2):

To a solution of P3-1 (100.0 g, 406.5 mmol) in pyridine (750 mL) wasadded DMTrCl (164.9 g, 487.8 mmol). The solution was stirred at R.T. for15 hours. MeOH (300 mL) was added, and the mixture was concentrated todryness under reduced pressure. The residue was dissolved in EtOAc andwashed with water. The organic layer was dried over Na₂SO₄ andconcentrated. The residue was dissolved in DCM (500 mL). Imidazole (44.3g, 650.4 mmol) and TBSCl (91.9 g, 609.8 mmol) was added. The reactionmixture was stirred at R.T. for 14 hours. The reaction solution waswashed with NaHCO₃ and brine. The organic layer was dried over Na₂SO₄,and concentrated to give the crude as a light yellow solid. The crude(236.4 g, 356.6 mmol) was dissolved in 80% HOAc aq. solution (500 mL).The mixture was stirred at R.T. for 15 hours. The mixture was dilutedwith EtOAc and washed with a NaHCO₃ solution and brine. The organiclayer was dried over Na₂SO₄ and purified by silica gel columnchromatography (1-2% MeOH in DCM) to give P3-2 (131.2 g, 89.6%) as alight yellow solid. ¹H NMR (DMSO-d6, 400 MHz) δ 11.39 (s, 1H), 7.88 (d,J=7.2 Hz, 1H), 5.89 (dd, J₁=18.0 Hz, J₂=2.0 Hz, 1H), 5.64 (d, J=8.0 Hz,1H), 5.21 (dd, J₁=J₂=7.2 Hz, 1H), 5.18˜5.03 (m, 1H), 4.37˜4.29 (m, 1H),3.86 (dd, J₁=J₂=3.2 Hz, 3H), 3.78˜3.73 (m, 1H), 3.51˜3.56 (m, 1H), 3.31(s, 1H), 0.89 (s, 9H), 0.11 (s, 6H); ESI-MS: m/z 802 [M+H]⁺.

Preparation of (P3-3):

To a solution of P3-2 (131.2 g, 364.0 mmol) in anhydrous CH₃CN (1200 mL)was added IBX (121.2 g, 432.8 mmol) at R.T. The reaction mixture wasrefluxed for 3 hours and then cooled to 0° C. The precipitate wasfiltered-off, and the filtrate was concentrated to give the crudealdehyde (121.3 g) as a yellow solid. The aldehyde was dissolved in1,4-dioxane (1000 mL). 37% CH₂O (81.1 mL, 1.3536 mol) and 2M NaOH aq.solution (253.8 mL, 507.6 mmol) were added. The mixture was stirred atR.T. for 2 hours and then neutralized with AcOH to pH=7. To the solutionwere added EtOH (400 mL) and NaBH₄ (51.2 g, 1.354 mol). The mixture wasstirred at R.T. for 30 minutes. The mixture was quenched with saturatedaq. NH₄Cl and extracted with EA. The organic layer was dried over Na₂SO₄and concentrated. The residue was purified by silica gel columnchromatography (1-3% MeOH in DCM) to give P3-3 (51.4 g, 38.9%) as awhite solid.

Preparation of (P3-4):

To a solution of P3-3 (51.4 g, 131.6 mmol) in anhydrous DCM (400 mL)were added pyridine (80 mL) and DMTrCl (49.1 g, 144.7 mmol) at 0° C. Thereaction was stirred at R.T. for 14 hours, and then treated with MeOH(30 mL). The solvent was removed, and the residue was purified by silicagel column chromatography (1-3% MeOH in DCM) to give a mono-DMTrprotected intermediate as a yellow foam (57.4 g, 62.9%). To theintermediate (57.4 g, 82.8 mmol) in CH₂Cl₂ (400 mL) was added imidazole(8.4 g, 124.2 mmol) and TBDPSCl (34.1 g, 124.2 mmol). The mixture wasstirred at R.T. for 14 hours. The precipitate was filtered off, and thefiltrate was washed with brine and dried over Na₂SO₄. The solvent wasremoved to give the residue (72.45 g) as a white solid. The solid wasdissolved in 80% HOAc aq. solution (400 mL). The mixture was stirred atR.T. for 15 hours. The mixture was diluted with EtOAc and washed withNaHCO₃ solution and brine. The organic layer was dried over Na₂SO₄ andpurified by silica gel column chromatography (1-2% MeOH in DCM) to giveP3-4 (37.6 g, 84.2%) as a white solid. ¹H NMR (CD₃OD, 400 MHz) δ 7.76(d, J=4.0 Hz, 1H), 7.70 (dd, J₁=1.6 Hz, J₂=8.0 Hz, 2H), 7.66˜7.64 (m,2H), 7.48˜7.37 (m, 6H), 6.12 (dd, J₁=2.8 Hz, J₂=16.8 Hz, 1H), 5.22 (d,J=8.0 Hz, 1H). 5.20˜5.05 (m, 1H), 4.74 (dd, J₁=5.6 Hz, J₂=17.6 Hz, 1H),4.16 (d, J=12.0 Hz, 1H), 3.87˜3.80 (m, 2H), 3.56 (d, J=12.0 Hz, 1H),1.16 (s, 9H), 0.92 (s, 9H), 0.14 (s, 6H).

Preparation of (P3-5):

To a solution of P3-4 (11.8 g, 18.8 mmol) in anhydrous DCM (100 mL) wasadded Dess-Martin periodinane (16.3 g, 37.6 mmol) at 0° C. undernitrogen. The reaction was stirred R.T. for 2.5 hours. Water (100 mL)was added, and the mixture was then filtered. The filtrate was washedwith saturated aq. NaHCO₃ and concentrated. The crude residue waspurified by silica gel column chromatography (20% EtOAc in hexane) togive P3-5 as a white solid (10.1 g, 86.0%).

Preparation of (P3-6):

To a mixture of methyltriphenylphosphonium bromide (15.7 g, 48.5 mmol)in anhydrous THF (100 mL) was added n-BuLi (19.4 mL, 48.48 mmol) at −78°C. under nitrogen. The reaction was stirred at 0° C. for 30 minutes. Asolution of P3-5 (10.1 g, 16.2 mmol) in anhydrous THF (70 mL) was addeddropwise at 0° C. under nitrogen. The reaction was stirred at R.T. for1.5 hours. The reaction was quenched by NH₄Cl and extracted with EtOAc.The crude product was purified by silica gel column chromatography (20%EtOAc in hexane) to give P3-6 as a white solid (8.3 g, 82.2%). ¹H NMR(CDCl₃, 400 MHz) δ 8.16 (s, 1H), 8.81 (d, J=8.0 Hz, 1H), 7.58-7.67 (m,4H), 7.37-7.46 (m, 6H), 6.17 (d, J=16.0 Hz, 1H), 5.91 (dd, J₁=10.8 Hz,J₂=17.6 Hz, 1H), 5.42 (d, J=17.6 Hz, 1H), 5.22-5.30 (m, 2H), 4.60-4.84(m, 2H), 3.69 (dd, J₁=11.6 Hz, J₂=21.2 Hz, 2H), 1.10 (s, 9H), 0.91 (s,1H), 0.12 (d, J=8.0 Hz, 6H).

Preparation of (P3-7):

To a solution of P3-6 (6.3 g, 10.09 mmol) in anhydrous CH₃CN (50 mL)were added TPSCl (6.1 g, 20.2 mmol), DMAP (2.5 g, 20.2 mmol) and NEt₃ (3mL) at R.T. The reaction was stirred at R.T. for 2 hours. NH₄OH (25 mL)was added, and the reaction was stirred for 1 hour. The mixture wasdiluted with DCM (150 mL) and washed with water, 0.1M HCl and saturatedaq. NaHCO₃. The solvent was removed, and the crude product was purifiedby silica gel column chromatography (2% MeOH in DCM) to give P3-7 as ayellow solid (5.9 g, 93.6%).

Preparation of (P3-8):

To a solution of P3-7 (5.9 g, 9.5 mmol) in MeOH (10 mL) was added Pd/C(1.5 g) at R.T. The reaction was stirred at R.T. for 2 hours under H₂(balloon). The mixture was filtered, and the filtrate was concentratedin vacuo to give P3-8 as a white solid (5.4 g, 91.3%).

Preparation of (3a):

To a solution of P3-8 (5.4 g, 8.6 mmol) in MeOH (60 mL) was added NH₄F(10.0 g), and the reaction mixture was refluxed overnight. After coolingto R.T., the mixture was filtered, and the filtrate was concentrated.The crude product was purified by silica gel column chromatography (10%MeOH in DCM) to give compound 3a as a white solid (1.6 g, 67.8%). ¹H NMR(CD₃OD, 400 MHz) δ 8.08 (d, J=7.6 Hz, 1H), 6.07 (dd, J₁=3.2 Hz, J₂=15.6Hz, 1H), 5.88 (d, J=7.2 Hz, 1H), 5.04 (ddd, J₁=3.2 Hz, J₂=5.2 Hz,J₃=54.0 Hz, 1H), 4.45 (dd, J₁=5.2 Hz, J₂=17.2 Hz, 1H), 3.76 (d, J=12.0Hz, 1H), 3.57 (d, J=12.0 Hz, 1H), 1.78-1.85 (m, 1H), 1.58-1.67 (m, 1H),0.95 (t, J=7.6 Hz, 3H); ESI-MS: m/z 274 [M+H]⁺, 547 [2M+H]⁺.

Example 4 Preparation of Compound (4a)

To a solution of P3-7 (280 mg, 0.45 mmol) in MeOH (10 mL) was added NH₄F(1.0 g) at R.T. The reaction mixture was refluxed for 5 hours. Aftercooling to R.T., the mixture was filtered, and the filtrate wasconcentrated. The crude product was purified by silica gel columnchromatography (10% MeOH in DCM) to give compound 4a as a white solid(82 mg, 67.2%1.6 g, 67.8%). ¹H NMR (CD₃OD, 400 MHz) δ 8.11 (d, J=7.6 Hz,1H), 5.99-6.08 (m, 2H), 5.88 (d, J=7.6 Hz, 1H), 5.47 (dd, J₁=1.2 Hz,J₂=17.2 Hz, 1H), 5.26 (dd, J₁=1.6 Hz, J₂=11.2 Hz, 1H), 4.97 (d, J=5.2Hz, 0.5H), 4.82 (d, J=7.6 Hz, 0.5H), 4.52 (dd, J₁=5.2 Hz, J₂=23.2 Hz,1H), 3.65 (d, J=12.4 Hz, 1H), 3.54 (d, J=12.4 Hz, 1H); ESI-MS: m/z 272[M+H]⁺, 543 [2M+H]⁺.

Example 5 Preparation of Compound (5a)

Preparation of (P5-1):

To a solution of P3-6 (600 mg, 0.96 mmol) in MeOH (30 mL) was added 10%Pd/C (320 mg) at R.T. The mixture was stirred under H₂ balloon at R.T.for 3 hours. The reaction mixture was filtered, and the filtrate wasconcentrated to give P5-1 (540 mg, 89.8%) as a colorless solid. Thecrude product was used directly for the next step without purification.

Preparation of (5a):

To a solution of P5-1 (540 mg, 0.86 mmol) in MeOH (8 mL) was added NH₄F(1.2 g, 32.4 mmol) R.T. The mixture was refluxed for 30 hours. The solidwas removed by filtration, and the filtrate was concentrated. Theresidue was purification by silica gel column chromatography (2.5%-9%MeOH in DCM) to give compound 5a (190 mg, 80.6%) as a colorless solid.¹H NMR (CD₃OD, 400 MHz) δ 8.05 (d, J=8.0 Hz, 1H), 6.09 (dd, J₁=4.0 Hz,J₂=14.8 Hz, 1H), 5.04-5.20 (m, 1H), 4.42 (dd, J₁=5.2 Hz, J₂=13.6 Hz,1H), 3.71 (d, J=11.6 Hz, 1H), 3.57 (d, J=12.0 Hz, 1H), 1.61-1.82 (m,2H), 0.94 (t, J=7.2 Hz, 3H).

Example 6 Preparation of Compound (6a)

Preparation of (P6-1):

To a solution of P3-3 (800 mg, 2.05 mmol) in anhydrous DCM (15 mL) wereadded imidazole (558 mg, 8.2 mmol), TBSCl (1.2 g, 8.2 mmol) and AgNO₃(700 mg, 4.1 mmol) at R.T. The reaction mixture was stirred at R.T.overnight. The mixture was filtered, and the filtrate was washed withbrine and concentrated in vacuo. The residue was purified by columnchromatography on silica gel to give P6-1 as a white solid (950 mg,79.2%).

Preparation of (6a):

To a solution of P6-1 (600 mg, 0.97 mmol) in anhydrous CH₃CN (18 mL) wasadded DMAP (239 mg, 2.91 mmol), NEt₃ (294 mg, 2.91 mmol) and TPSCl (879mg, 2.91 mmol) at R.T. The reaction was stirred at R.T. for 1 hour.NH₄OH (9 mL) was added, and the reaction was stirred for 3 hours. Themixture was diluted with EtOAc (200 mL) and washed with water, 0.1M HCland saturated aq. NaHCO₃. The organic layer was separated, dried andconcentrated to give a crude residue. The crude residue was purified bycolumn chromatography on silica gel to give the product as a white solid(500 mg, 83.3%). The solid was treated with NH₄F (1.0 g) in MeOH (20 mL)at refluxed temperature for 5 hours. The mixture was filtered, and thefiltrate was concentrated in vacuo. The residue was purified by columnchromatography on silica gel (15% MeOH in DCM) to give compound 6a as awhite solid (132 mg, 59.3%). ¹H NMR (DMSO-d6, 400 MHz) δ 7.89 (d, J=7.6Hz, 1H), 7.22 (d, J=18.8 Hz, 2H), 6.09 (dd, J₁=4.4 Hz, J₂=14.8 Hz, 1H),5.73 (d, J=5.2 Hz, 1H), 5.52 (d, J=5.6 Hz, 1H), 5.12 (t, J=4.8 Hz, 1H),4.90-5.06 (m, 1H), 4.50 (t, J=6.0 Hz, 1H), 4.27-4.33 (m, 1H), 3.66 (dd,J₁=5.2 Hz, J₂=12.0 Hz, 1H), 3.47-3.58 (m, 3H); ESI-MS: m/z 276 [M+H]⁺,551 [2M+H]⁺.

Example 7 Preparation of Compound (7a)

Preparation of (P7-1):

A mixture of P3-4 (1.60 g, 2.5 mmol), PPh₃ (1.3 g, 5.0 mmol) and CCl₄(0.76 g, 5.0 mmol) in DCE (20 mL) was heated to 130° C. under microwaveirradiation under N₂ for 40 mins. After cooled to R.T., the solvent wasremoved, and the residue was purified on a silica gel column (PE/EA=50/1to 10/1) to give P7-1 (1.1 g, 68.8%) as a white solid.

Preparation of (P7-2):

P7-1 (0.80 g, 1.3 mmol), DMAP (0.3 g, 2.6 mmol), TPSCl (0.8 g, 2.6 mmol)and Et₃N (0.3 g, 2.6 mmol) were dissolved in MeCN (30 mL). The mixturewas stirred at R.T. for 14 hours. NH₃ in THF (saturated at 0° C., 100mL) was added to the mixture, and the mixture was stirred at R.T. for 2hours. The solvent was removed, and the residue was purified by column(DCM/MeOH=100:1 to 50:1) to give P7-2 (0.63 g, 78.8%) as a white solid.

Preparation of (7a):

To a solution of P7-2 (0.63 g, 0.98 mmol) in MeOH (10 mL) was added NH₄F(0.3 g), and the reaction was refluxed for 12 hours. The reaction wascooled to R.T., and the precipitate was filtered off. The filtrate wasconcentrated in vacuo. The residue was purified by silica gel columnchromatography (10% MeOH in DCM) to give compound 7a as a white solid(153 mg, 53.5%). ¹H NMR (CD₃OD, 400 MHz) δ 8.05 (d, J=7.2 Hz, 1H), 6.14(dd, J₁=3.6 Hz, J₂=15.2 Hz, 1H), 5.92 (d, J=7.2 Hz, 1H), 5.15 (ddd,J₁=4.0 Hz, J₂=5.2 Hz, J₃=53.6 Hz, 1H), 4.57 (dd, J₁=4.8 Hz, J₂=15.2 Hz,1H), 3.93 (d, J=11.6 Hz, 1H), 3.75-3.84 (m, 3H); ESI-MS: m/z 294 [M+H]⁺,587 [2M+H]⁺.

Example 8 Preparation of Compound (8a)

To a solution of P7-1 (630 mg, 0.5 mmol) in MeOH (10 mL) was added NH₄F(0.1 g), and the reaction was refluxed for 12 hours. The mixture wasfiltered, and the filtrate was concentrated in vacuo. The crude productwas purified by silica gel column chromatography (10% MeOH in DCM) togive compound 8a as a white solid (153 mg, 53.5%). ¹H NMR (CD₃OD, 400MHz) δ 7.99 (d, J=8.0 Hz, 1H), 6.17 (dd, J₁=4.4 Hz, J₂=14.4 Hz, 1H),5.70 (d, J=8.0 Hz, 1H), 5.22 (ddd, J₁=J₂=4.8 Hz, J₃=53.2 Hz, 1H), 4.55(dd, J₁=5.2 Hz, J₂=12.4 Hz, 1H), 3.88 (d, J=12.0 Hz, 1H), 3.76-3.79 (m,3H); Negative-ESI-MS: m/z 293 [M−H]⁻.

Example 9 Preparation of Compound (9a)

Preparation of (P9-1):

A mixture of P3-4 (3.2 g, 5.0 mmol), Ph₃P (5.2 g, 20 mmol), iodine (2.60g, 10.2 mmol) and imidazole (1.4 g, 20 mmol) in anhydrous THF (40 mL)was stirred at 80° C. for 14 hours. The reaction was cooled to R.T. andquenched with saturated aq. Na₂S₂O₃. The solution was extracted with EA.The organic layer was dried over Na₂SO₄ and concentrated. The residuewas purified by silica gel column chromatography (20-50% EA in PE) togive P9-1 (1.6 g, 68.2%) as a white solid.

Preparation of (P9-2):

A mixture of P9-1 (1.4 g, 0.2 mmol), Et₃N (40 mg, 0.4 mmol) and Pd/C inEtOH (20 mL) was stirred at R.T. under H₂ (balloon) overnight. Theprecipitate was filtered off, and the filtrate was concentrated. Theresidue was purified on a silica gel column (20%-50% EtOAc in PE) togive P9-2 as a white solid (1.1 g, 78%). ¹H NMR (CDCl₃, 400 MHz) δ 8.11(br s, 1H), 7.76 (d, J=8.0 Hz, 1H), 7.39-7.67 (m, 10H), 6.18 (dd, J₁=3.2Hz, J₂=14.4 Hz, 1H), 5.26-5.30 (m, 1H), 4.86 (m, 1H), 4.42 (dd, J₁=5.2Hz, J₂=15.2 Hz, 1H), 3.81 (d, J=11.2 Hz, 1H), 3.58 (d, J=11.2 Hz, 1H),1.16 (s, 3H), 1.11 (s, 9H), 0.91 (s, 9H), 0.13 (s, 3H), 0.08 (s, 3H).

Preparation of (P9-3):

P9-2 (650 mg, 1.1 mmol), DMAP (270 mg, 2.2 mmol), TPSCl (664 mg, 2.2mol) and Et₃N (222 mg, 2.2 mmol) were dissolved in MeCN (20 mL). Themixture was stirred at R.T. for 14 hours. The reaction was added NH₃ inTHF (saturated at 0° C.), and the mixture was stirred at R.T. for 2hours. The solvent was removed, and the residue was purified on a silicagel column (1-10% MeOH in DCM) to give P9-3 (430 mg, crude) as a lightyellow syrup.

Preparation of (9a):

A mixture of P9-3 (430 mg, 0.7 mmol) and NH₄F (97 mg, 2.1 mmol) in MeOH(10 mL) was refluxed for 14 hours. The solvent was removed, and theresidue was purified on a silica gel column (5%-10% MeOH in DCM) to givecompound 9a as a white solid (64.8 mg, 35.4%). ¹H NMR (CD₃OD, 400 MHz) δ8.10 (d, J=7.6 Hz, 1H), 6.03 (dd, J₁=2.0 Hz, J₂=16.8 Hz, 1H), 5.87 (d,J=7.6 Hz, 1H), 4.98 (m, 1H), 4.37 (dd, J₁=5.2 Hz, J₂=21.6 Hz, 1H), 3.59(dd, J₁=12.0 Hz, J₂=28.4 Hz, 2H), 1.23 (d, J=0.8 Hz, 3H).

Example 10 Preparation of Compound (10a)

To a stirred solution of P9-2 (400 mg, 0.65 mmol) in MeOH (20 mL) wasadded NH₄F (52 mg, 1.5 mmol). The mixture was refluxed overnight. Thesolvent was removed, and the residue was purified on a silica gel column(5-10% MeOH in DCM) to give compound 10a (140 mg, 82.4%) as a whitesolid. ¹H NMR (CD₃OD, 400 MHz) δ 8.05 (d, J=8.4 Hz, 1H), 6.06 (dd,J₁=2.8 Hz, J₂=16.4 Hz, 1H), 5.67 (d, J=8.0 Hz, 1H), 5.08 (m, 1H), 4.37(d, J₁=5.2 Hz, J₂=18.8 Hz, 1H), 3.59 (dd, J₁=12.0 Hz, J₂=26.4 Hz, 2H),1.23 (s, 3H). ESI-TOF-MS: m/z 283 [M+Na]⁺.

Example 11 Preparation of Compound (11a)

Preparation of (P11-1):

To a solution of P3-5 (2.1 g, 3.5 mmol) in anhydrous THF (25 mL) wasadded ethynylmagnesium bromide (5.1 mmol) at −78° C. The reaction wasstirred at 0° C. for 3 hours. The reaction was quenched with saturatedaq. NH₄Cl (10 mL). The mixture was diluted with EtOAc (200 mL) andwashed with water and brine. The organic layer was dried andconcentrated to give a residue. The residue was purified by columnchromatography on silica gel (eluting with DCM:MeOH=60:1) to give P11-1as a white solid (870 mg, 83.3%).

Preparation of (P11-2):

P11-1 (870 mg, 1.34 mmol) was dissolved in anhydrous DCM (12 mL), andmethyl chloroformate (2.3 mL) and pyridine (2.5 mL) were added at R.T.The reaction mixture was stirred at R.T. for 1 hour. The mixture wasdiluted with DCM and washed with saturated aq. NaHCO₃. The organic layerwas separated, dried and concentrated to give a residue. The residue waspurified by column chromatography on silica gel (eluting withPE:EtOAc=8:1) to give a crude product as a white solid (830 mg, 88.4%).To a mixture of Pd₂(dba)₃ (55 mg, 0.06 mmol) in anhydrous DMF (12 mL)was added P(nBu)₃ (35 mg, 0.17 mmol) and HCOONH₄ (108 mg, 1.7 mmol) atR.T. under nitrogen. The reaction mixture was stirred at R.T. for 30min. A solution of the crude product (830 mg, 1.16 mmol) in anhydrousDMF (16 mL) was added, and the reaction mixture was stirred at 70° C.for 3 hours. The reaction was diluted with EtOAc and washed with brine.The organic layer was separated, dried and concentrated to give aresidue. The residue was purified by column chromatography on silica gel(eluting with PE:EtOAc=9:1) to give P11-2 as a white solid (510 mg,67.6%). ¹H NMR (CD₃OD, 400 MHz) δ 7.61-7.75 (m, 5H), 7.36-7.47 (m, 6H),6.04 (d, J=18.8 Hz, 1H), 5.34 (t, J=6.8 Hz, 1H), 5.21 (dd, J₁=1.2 Hz,J₂=7.2 Hz, 1H), 5.10 (q, J₁=5.2 Hz, J₂=53.6 Hz, 1H), 4.80-4.92 (m, 1H),4.59-4.79 (m, 2H), 3.86 (d, J=12.0 Hz, 1H), 3.75 (d, J=12.0 Hz, 1H),1.09 (s, 9H), 0.92 (d, J=4.4 Hz, 9H), 0.15 (t, J=4.0 Hz, 6H).

Preparation of (P11-3):

To a solution of P11-2 (490 mg, 0.77 mmol) in anhydrous MeCN (15 mL) wasadded TPSCl (700 mg, 2.31 mmol), DMAP (282 mg, 2.31 mmol) and TEA (234mg, 2.31 mmol) at R.T. The reaction mixture was stirred at roomtemperature for 1 hour. Then NH₄OH (8 mL) was added and the reactionmixture was stirred for another 4 hours. The mixture was diluted withEtOAc and washed with water, 1.0 M aq. HCl and saturated aq. NaHCO₃. Theorganic layer was separated and dried, concentrated to give the residuewhich was purified by HPLC separation (MeCN and 0.1% HCOOH in water) togive P11-3 as a white solid (190 mg, 38.8%). ¹H NMR (CD₃OD, 400 MHz) δ7.88 (d, J=7.2 Hz, 1H), 7.63-7.70 (m, 4H), 7.37-7.48 (m, 6H), 6.12 (d,J=18.4 Hz, 1H), 5.49 (d, J=7.6 Hz, 1H), 5.34 (t, J=6.8 Hz, 1H),4.84-5.01 (m, 2H), 4.66-4.78 (m, 2H), 3.89 (d, J=11.6 Hz, 1H), 3.75 (d,J=11.6 Hz, 1H), 1.10 (s, 9H), 0.91 (d, J=3.2 Hz, 9H), 0.13 (t, J=5.2 Hz,6H).

Preparation of (11a):

To a solution of P11-3 (130 mg, 0.21 mmol) in MeOH (8 mL) was added NH₄F(1 g), and the reaction mixture was refluxed for 6 hours. The mixturewas filtered, and the filtrate was concentrated in vacuo. The residuewas purified by column chromatography on silica gel (eluting withDCM:MeOH=13:1) to give compound 11a as a white solid (47 mg, 79.1%). ¹HNMR (CD₃OD, 400 MHz) δ 8.07 (d, J=7.6 Hz, 1H), 6.05 (dd, J₁=1.2 Hz,J₂=16.8 Hz, 1H), 5.86 (d, J=7.6 Hz, 1H), 5.40 (dd, J₁=J₂=6.8 Hz, 1H),4.87-4.99 (m, 3H), 4.46-4.80 (m, 1H), 3.75 (d, J=12.4 Hz, 1H), 3.68 (d,J=12.4 Hz, 1H); ESI-MS: m/z 284.02 [M+H]⁺, 567.08 [2M+H]⁺.

Example 12 Preparation of Compound (12a)

Preparation of (P12-1):

To a solution of P3-4 (500 mg, 0.8 mmol) in anhydrous toluene (12 mL)was added DAST (0.3 mL, 2 mmol) at −65° C. under nitrogen. The reactionmixture was stirred at R.T. for 2 hours. The reaction was quenched withsaturated aq. NaHCO₃ and extracted with EtOAc. The organic layer wasseparated, dried and concentrated to give the residue. The residue waspurified by column chromatography on silica gel (eluting withPE:EtOAc=9:1) to give P12-1 as a yellow solid (170 mg, 42.5%). ¹H NMR(CD₃OD, 400 MHz) δ 7.66 (dd, J₁=1.6 Hz, J₂=18.0 Hz, 4H), 7.54 (d, J=7.6Hz, 1H), 7.35-7.47 (m, 6H), 6.59 (dd, J₁=5.6 Hz, J₂=14.0 Hz, 1H), 5.78(d, J=7.6 Hz, 1H), 5.05-5.24 (m, 2H), 4.93 (d, J=7.6 Hz, 1H), 4.57 (d,J=7.6 Hz, 1H), 3.93-4.00 (m, 2H), 1.07 (d, J=2.4 Hz, 9H).

Preparation of (P12-2):

To a solution of P12-1 (100 mg, 0.2 mmol) in anhydrous MeCN (5 mL) wasadded TPSCl (182 mg, 0.6 mmol), DMAP (68 mg, 0.6 mmol) and TEA (61 mg,0.6 mmol) at R.T. under nitrogen. The reaction mixture was stirred atR.T. for 1 hour. NH₄OH (3 mL) was added, and the reaction was stirredfor 2 hours. The mixture was diluted with EtOAc and washed with water,1.0 M HCl and saturated aq. NaHCO₃. The organic layer was separated,dried and concentrated to give a residue. The residue was purified bycolumn chromatography on silica gel (DCM:MeOH=50:1) to give P12-2 as ayellow solid (96 mg, 96%).

Preparation of (12a):

To a solution of P12-2 (96 mg, 0.2 mmol) in MeOH (5 mL) was added NH₄F(500 mg) at R.T. The reaction was refluxed for 3 hours. The mixture wasfiltered, and the residue was purified by RP HPLC (MeCN and 0.1% HCOOHin water) to give compound 12a as a white solid (25 mg, 48.7%). ¹H NMR(CD₃OD, 400 MHz) δ 7.85 (d, J=7.6 Hz, 1H), 6.59 (dd, J₁=5.2 Hz, J₂=12.8Hz, 1H), 6.04 (d, J=7.6 Hz, 1H), 5.10-5.26 (m, 2H), 4.79-4.90 (m, 1H),4.57 (d, J=7.6 Hz, 1H), 3.82 (d, J=12.4 Hz, 1H), 3.76 (dd, J₁=1.6 Hz,J₂=12.4 Hz, 1H); ESI-MS: m/z 257.9 [M+H]⁺, 514.8 [2M+H]⁺.

Example 13 Preparation of Compound (13a)

Preparation of (P13-1):

To a solution of compound 3a (700 mg, 2.56 mmol) in anhydrous pyridine(5 mL) were added TBDPSCl (2.8 g, 10.24 mmol), imidazole (522 mg, 7.68mmol) and AgNO₃ (870 mg, 5.12 mmol) at R.T. under N₂. The reactionmixture was stirred at R.T. for 3 hours. The mixture was diluted withMeOH and filtered. The mixture was concentrated, and the residue waspurified by column chromatography on silica gel (eluting withDCM:MeOH=80:1˜40:1) to give the crude intermediate as a yellow solid(1.05 g, 80.8%). ¹H NMR (DMSO-d6, 400 MHz) δ 7.75 (d, J=7.6 Hz, 1H),7.61-7.65 (m, 4H), 7.41-7.50 (m, 7H), 6.02 (dd, J₁=2.8 Hz, J₂=17.2 Hz,1H), 5.69 (d, J=6.0 Hz, 1H), 5.56 (d, J=7.6 Hz, 1H), 4.96-5.11 (m, 1H),4.37-4.46 (m, 1H), 3.82 (d, J=10.8 Hz, 1H), 3.62 (d, J=10.8 Hz, 1H),1.70-1.78 (m, 1H), 1.53-1.59 (m, 1H), 1.02 (s, 9H), 0.79 (t, J=7.6 Hz,3H). To a solution of the crude intermediate (1.0 g, 1.96 mmol) inanhydrous DCM (15 mL) were added sym-collidine (1.4 g, 11.76 mmol),AgNO₃ (1.0 g, 5.88 mmol) and MMTrCl (4.8 g, 15.6 mmol) at R.T. under N₂.The reaction mixture was stirred at R.T. overnight. The mixture wasfiltered and concentrated. The residue was purified by columnchromatography on silica gel (eluting with PE:EtOAc=2:1) to give crudefull protected intermediates as a white solid (1.1 g, 53.1%). To asolution of the crude intermediate (600 mg, 0.57 mmol) in THF (5 mL) wasadded TBAF (446 mg, 1.71 mmol)) at R.T. The reaction was stirred at40-50° C. overnight. The crude product was purified by columnchromatography on silica gel eluted with PE:EtOAc=3:2 to give crudeP13-1 (350 mg, 75.1%) as a yellow solid.

Preparation of (13a):

To a solution of P13-1 (300 mg, 0.37 mmol) in CH₃CN (2.5 mL) were addedNMI (2.5 mL) and a solution of phenyl(isopropoxy-L-alaninyl)phosphorochloridate (2.55 g, 7.4 mmol) in CH₃CN (2.5 mL) at R.T. underN₂. The reaction mixture was stirred at R.T. for 3 hours. The mixturewas concentrated in vacuo. The residue was purified by columnchromatography on silica gel (PE:EtOAc=1:1) to give crude product as ayellow oil (500 mg, 81%). The crude product was further treated with 80%HCOOH (70 mL) at R.T. overnight. The mixture was concentrated in vacuo,and the crude product was purified by RP HPLC (MeCN and 0.1% HCOOH inwater) to give compound 13a as a white solid (a mixture of two βisomers, 86 mg, 40.3% two steps). ¹H NMR (CD₃OD, 400 MHz) δ 7.75, 7.71(2d, J=7.6 Hz, 1H), 7.33-7.38 (m, 2H), 7.19-7.26 (m, 3H), 6.02-6.10 (m,1H), 5.87, 5.82 (2d, J=7.6 Hz, 1H), 4.99-5.02 (m, 0.5H), 4.72-4.82 (m,1.5H), 4.14-4.43 (m, 3H), 3.89-3.94 (m, 1H), 1.68-1.81 (m, 6H),1.51-1.56 (m, 1H), 1.30-1.43 (m, 8H), 0.96-1.01 (m, 3H); ESI-MS: m/z582.93 [M+H]⁺.

Example 14 Preparation of Compound (14a)

Preparation of (P14-1):

To a stirred solution of P13-1 (451 mg, 0.55 mmol) and NMI (1 mL) inanhydrous acetonitrile (2 mL) was added dropwise a solution of2-chloro-8-methyl-4H-benzo[d][1,3,2]dioxaphosphinine (855 mg, 4.2 mmol)in acetonitrile (0.2 mL) at 0° C. under N₂. The mixture was stirred atR.T. for 2 hours. Solution of I₂ (3.2 g, 12.6 mmol), pyridine (9 mL),H₂O (3 mL) and DCM (3 mL) was added. The reaction mixture was stirredfor 30 mins. The reaction was quenched with NaS₂O₃ solution andextracted with EA. The organic layer was dried over Na₂SO₄ andconcentrated. The residue was purified by column on silica gel(PE:EA=1:1 to 1:2) to give P14-1 (205 mg, 37%) as a white solid.

Preparation of (14a):

P14-1 (205 mg, 0.21 mmol) was dissolved in 80% HCOOH aq. solution, andthe mixture was stirred at R.T. for 16 hours. The solvent was removed,and the residue was purified by RP HPLC(HCOOH system) to give compound14a as a mixture of 2 P-isomers (24 mg, 18%). ¹H NMR (CD₃OD, 400 MHz) δ7.60, 7.53 (2d, J=8.0 Hz, 1H), 7.21-7.25 (m, 1H), 7.02-7.12 (m, 2H),5.95. 5.87 (2dd, J₁=2.4 Hz, J₂=18.0 Hz, 1H), 5.71, 5.69 (2d, J=8.0 Hz,1H), 5.38-5.53 (m, 2H), 5.06, 5.04 (2ddd, J₁=2.4 Hz, J₂=5.6 Hz, J₃=54.0Hz, 1H), 4.32-4.49 (m, 2H), 2.26 (d, J=3.6 Hz, 3H), 1.83-1.92 (m, 1H),1.64-1.72 (m, 1H), 0.96, 0.93 (2t, J=7.6 Hz, 3H). ³¹P NMR (CD₃OD, 162MHz) δ −8.22, −8.50; ESI-LCMS: m/z 456 [M+H]⁺.

Example 15 Preparation of Compound (15a)

Step 1. Preparation of (P15-1):

To a mixture of P3-8 (2.2 g, 2.5 mmol), AgNO₃ (844 mg, 5.0 mmol) andcollidine (907 mg, 7.5 mmol) in anhydrous DCM (10 mL) was added MMTrCl(1.54 g, 5.0 mmol) under N₂. The reaction mixture was stirred at R.T.overnight. The reaction mixture was filtered through a Buchner Funnel.The filtrate was washed with saturated NaHCO₃ solution and brine. Theorganic layer was separated, dried over anhydrous Na₂SO₄ and filtered.The filtrate was concentrated to dryness. The residue was purified bycolumn on silica gel (PE:EA=10:1 to 1:2) to give the intermediate (2.3g, 84%), which was dissolved in a solution of TBAF in THF (1M, 2.6 mL)under N₂. The reaction mixture was stirred at R.T. overnight. Theresidue was dissolved in EA (200 mL) and washed with water and brine.The organic layer was separated, dried over anhydrous Na₂SO₄ andfiltered. The filtrate was concentrated to dryness, and the residue waspurified by column on silica gel (DCM/MeOH=100:1 to 30:1) to give P15-1as a white foam (1.3 g, 94%).

Preparation of (15a):

To a stirred solution of P15-1 (300 mg, 0.55 mmol) and proton sponge(235 mg, 1.1 mmol) in anhydrous MeCN (9 mL) was added with a solution ofPOCl₃ (169 mg, 1.1 mmol) in MeCN (1 mL) via syringe at 0° C. The mixturewas stirred at R.T. for 40 mins. A mixture of (S)-cyclohexyl2-aminopropanoate hydrochloride (525 mg, 2.55 mmol) and TEA (0.1 mL) wasadded at 0° C. The mixture was warmed to R.T. and stirred for 3 hours.The reaction mixture was quenched with saturated NaHCO₃, and extractedwith EA (100 mL×2). The combined organic layers was dried over Na₂SO₄,concentrated and purified by silica gel column (1˜4% MeOH in DCM) togive the crude product (400 mg, 78.15%) as a yellow solid. The crudeproduct was treated with 80% HCOOH (50 mL) at R.T. for 16 hours. Thesolvent was removed, and the residue was purified by RP HPLC to givecompound 15a as a white solid (40 mg, 14%). ¹H NMR (MeOD, 400 MHz) δ7.82 (d, J=7.6 Hz, 1H), 6.09 (dd, J₁=2.8 Hz, J₂=14.0 Hz, 1H), 5.98 (d,J=7.6 Hz, 1H), 5.04 (ddd, J₁=3.2 Hz, J₂=5.6 Hz, J₃=53.6 Hz, 1H),4.71-4.77 (m, 2H), 4.45 (dd, J₁=5.6 Hz, J₂=12.4 Hz, 1H), 4.14-4.18 (m,1H), 3.97-4.01 (m, 1H), 3.84-3.92 (m, 2H), 1.31-1.87 (m, 28H), 0.99 (t,J=7.2 Hz, 3H). ³¹P NMR (CD₃OD, 162 MHz) δ 13.94; ESI-LCMS: m/z 660[M+H]⁺.

Example 16 Preparation of Compound (16a)

To a stirred solution of compound 4a (150 mg, 0.56 mmol) in anhydrousTHF (3 mL) was added dropwise a solution of t-BuMgCl (1.2 mL, 1M in THF)at −78° C. The mixture was stirred at 0° C. for 30 min and re-cooled to−78° C. A solution of phenyl(isopropoxy-L-alaninyl) phosphorochloridate(312 mg, 1.2 mmol) in THF (1.0 mL) was added dropwise. After addition,the mixture was stirred at 25° C. for 16 hours. The reaction wasquenched with HCOOH (80% aq.) at 0° C. The solvent was removed, and theresidue was purified on silica gel (DCM:MeOH=50:1 to 10:1) to givecompound 16a as a white solid (24.0 mg, 15%). ¹H NMR (MeOD, 400 MHz) δ7.76 (d, J=7.2 Hz, 1H), 7.17-7.38 (m, 5H), 6.01-6.08 (m, 2H), 5.81 (d,J=7.6 Hz, 1H), 5.54-5.58 (m, 1H), 5.35-5.38 (m, 1H), 4.92-4.97 (m, 2H),4.45-4.52 (m, 1H), 4.08-4.19 (m, 2H), 3.88-3.92 (m, 1H), 1.28-1.33 (m,3H), 1.20-1.22 (m, 6H); ³¹P NMR (CD₃OD, 162 MHz) δ 7.36; ESI-LCMS: m/z541.0[M+H]⁺.

Example 17 Preparation of Compound (17a)

Preparation of (P17-1):

To a solution of P3-7 (1.4 g, 2.3 mmol) in MeOH (50 mL) was added NH₄F(8.0 g) at R.T. The reaction mixture was refluxed overnight. Aftercooling to R.T., the mixture was filtered, and the filtrate wasconcentrated. The crude product was purified by silica gel columnchromatography (10% MeOH in DCM) to give P17-1 as a white solid (410 mg,77.8%).

Preparation of (P17):

To a stirred solution of P17-1 (60 mg, 0.19 mmol) in anhydrous THF (3mL) was added dropwise a solution of t-BuMgCl (0.38 mL, 1M in THF) at−78° C. The mixture was stirred at 0° C. for 30 min and re-cooled to−78° C. A solution of phenyl(isopropoxy-L-alaninyl) phosphorochloridate(104 mg, 0.4 mmol) in THF (0.5 mL) was added dropwise. After addition,the mixture was stirred at 25° C. for 16 hours. The reaction wasquenched with HCOOH (80% aq.) at 0° C. The solvent was removed, and theresidue was purified on silica gel (DCM:MeOH=50:1 to 10:1) to givecompound 17a as a white solid (a mixture of two β isomers, 11.0 mg,11%). ¹H NMR (MeOD, 400 MHz) δ 7.71 (2d, J=8.0 Hz, 1H), 7.17-7.37 (m,5H), 5.98-6.07 (m, 2H), 5.61, 5.68 (2d, J=8.0 Hz, 1H), 5.53-5.58 (m,1H), 5.35-5.40 (m, 1H), 5.08-5.10 (m, 1H), 4.93-4.99 (m, 1H), 4.52-4.53(m, 1H), 4.16-4.21 (m, 1H), 4.06-4.11 (m, 1H), 3.86-3.94 (m, 1H),1.28-1.34 (m, 3H), 1.20-1.22 (m, 6H). ³¹P NMR (MeOD, 162 MHz) δ 3.72,3.45. ESI-LCMS: m/z 542.0 [M+H]⁺.

Example 18 Preparation of Compound (18a)

Preparation of (P18-1):

To a solution of (chloromethyl)triphenylphosphonium chloride (2.1 g, 6.0mmol) in anhydrous THF (10 mL) was added dropwise n-BuLi (4.6 mL, 6.0mmol) at −70° C. under nitrogen. The reaction was stirred at −70° C. for50 mins. A solution of compound P3-9 (950 mg, 1.5 mmol) in anhydrous THF(5 mL) was added at −70° C., and the reaction was stirred at 0° C. for 3hours. The reaction was quenched by saturated aq. NH₄Cl and extractedwith EtOAc. The organic layer was separated, dried and concentrated togive a residue. The residue was purified by column chromatography onsilica gel (eluting with PE:EtOAc=6:1) to give P18-1 as a yellow gum(900 mg, 91.2%).

Preparation of (P18-2):

To a solution of compound P18-1 (600 mg, 0.91 mmol) in anhydrous THF (18mL) was added dropwise n-BuLi (4.7 mL, 10.9 mmol) at −70° C. undernitrogen. The reaction was stirred at −70° C. for 3 hours. The reactionwas quenched by saturated aq. NH₄Cl and extracted with EtOAc. Theorganic layer was separated, dried and concentrated to give a residue.The residue was purified by column chromatography on silica gel (elutingwith PE:EtOAc=8:1˜5:1) to give P18-2 as a white solid (300 mg, 53.0%).

Preparation of (P18-3):

To a solution of P18-2 (300 mg, 0.44 mmol) in MeOH (10 mL) was addedNH₄F (1.0 g) at R.T. The reaction was refluxed for 3 hours. Aftercooling R.T., the mixture was filtered, and the filtrate wasconcentrated in vacuo. The residue was purified by column chromatographyon silica gel (eluting with DCM:MeOH=50:1˜30:1) to give P18-3 as a whitesolid (135 mg, 78.1%). ¹H NMR (CD₃OD, 400 MHz) δ 7.84 (d, J=8.0 Hz, 1H),6.06 (dd, J₁=1.6 Hz, J₂=19.6 Hz, 1H), 5.67 (d, J=8.4 Hz, 1H), 5.18-5.03(m, 1H), 4.50 (dd, J₁=5.2 Hz, J₂=21.6 Hz, 1H), 3.85 (d, J=12.4 Hz, 1H),3.72 (d, J=12.4 Hz, 1H), 3.09 (s, 1H).

Preparation of (18a):

To a solution of P18-3 (130 mg, 0.5 mmol) in anhydrous THF (4 mL) wasadded dropwise t-BuMgCl (1.0 mL, 1.0 mmol) at −70° C. under nitrogen.The reaction was stirred at R.T. for 30 mins. A solution ofphenyl(isopropoxy-L-alaninyl) phosphorochloridate in anhydrous THF (1M,0.8 mL, 0.78 mmol) was added at −70° C., and the reaction mixture wasstirred at R.T. for 5 hours. The reaction was quenched by HCOOH, and themixture was concentrated in vacuo. The residue was purified by columnchromatography on silica gel (DCM:MeOH=60:1) to give compound 18a as awhite solid (a mixture of two β isomers, 25 mg, 7.7%). ¹H NMR (CD₃OD,400 MHz) δ 7.64, 7.60 (2d, J=7.6 Hz, 1H), 7.32-7.36 (m, 2H), 7.16-7.25(m, 3H), 5.95-6.01 (m, 1H), 5.67, 5.62 (2d, J=8.0 Hz, 1H), 5.10-5.25 (m,1H), 4.93-4.97 (m, 1H), 4.49-4.59 (m, 1H), 4.33-4.42 (m, 1H), 4.24-4.29(m, 1H), 3.86-3.94 (m, 1H), 3.25, 3.22 (2s, 1H), 1.28-1.34 (m, 3H),1.20-1.23 (m, 6H); ESI-MS: m/z 540.2 [M+H]⁺.

Example 19 Preparation of Compound (19a)

Preparation of (P19-1):

P15-2 (1.2 g, 2.2 mmol) was dissolved in dry acetonitrile (20 mL), and0.45 M tetrazole (24.0 mL, 11.0 mmol) and3-(bis(diisopropylamino)phosphinooxy)propanenitrile (1.13 g, 3.74 mmol)was added. The reaction mixture was stirred for 1 hour under N₂ at R.T.TBDPH (2.7 mL, 15 mmol) was added, and the mixture was stirred for 1hour. The reaction was quenched by Na₂S₂O₃ solution and extracted withEA. The organic layer was dried over Na₂SO₄ and concentrated. Theresidue was purified by column on silica gel (DCM:MeOH=100:1 to 40:1) togive P19-1 as a white solid (759 mg, 52%).

Preparation of (P19-2):

P19-1 (750 mg, 1.14 mmol) was dissolved in saturated NH₃ in MeOHsolution. The mixture was stirred for 2 hours at R.T. The solution wasconcentrated to dryness to give crude P19-2 as a yellow solid (662 mg,100%). ¹H NMR (DMSO-d6, 400 MHz) δ 8.60 (s, 1H), 8.28 (s, 1H), 7.48 (d,J=7.6 Hz, 1H), 7.12-7.29 (m, 12H), 6.83 (d, J=8.8 Hz, 2H), 6.29 (d,J=7.6 Hz, 1H), 5.88 (d, J=8.8 Hz, 1H), 5.10 (d, J=4.8 Hz, 1H), 4.42-4.45(m, 1H), 3.72 (s, 3H), 1.64-1.91 (m, 2H), 1.10-1.13 (m, 2H), 0.83-0.86(m, 3H). ³¹P NMR (CD₃OD, 400 MHz) δ −4.48; Negative-ESI-LCMS: m/z 606[M−H]⁻.

Preparation of (P19-3):

P19-2 (292 mg, 0.47 mmol) was co-evaporated with pyridine twice anddissolved in anhydrous DMF (0.5 mL). DIPEA (1.2 mL) was added andfollowed by 2,2-dimethyl-propionic acid iodomethyl ester (680 mg, 2.8mmol). The reaction mixture was stirred at R.T. under N₂ for 16 hours.The reaction was quenched by Na₂S₂O₃ solution and extracted with EA. Theorganic layer was dried over Na₂SO₄ and concentrated. The residue waspurified by column on silica gel (DCM:MeOH=100:1 to 30:1) to give P19-3as a white solid (95 mg, 30%).

Preparation of (19a):

P19-3 (95 mg, 0.13 mmol) was dissolved in a 80% HCOOH aq. solution, andthe mixture was stirred at R.T. for 16 hours. The solvent was removed,and the residue was purified by RP HPLC (MeCN and 0.1% HCOOH in water)to give compound 19a as a white solid (10 mg, 17%). ¹H NMR (CD₃OD, 400MHz) δ 7.69 (d, J=7.2 Hz, 1H), 5.91 (d, J=7.6 Hz, 1H), 5.84 (d, J=22.0Hz, 1H), 5.73 (d, J=14.0 Hz, 2H), 5.52 (d, J=5.2 Hz, 1H), 5.13-5.22 (m,1H), 4.53-4.61 (m, 1H), 4.31 (d, J=9.6 Hz, 1H), 1.92-2.08 (m, 2H), 1.23(s, 9H), 1.03-1.07 (m, 3H); ³H NMR (CD₃OD, 162 MHz) δ −7.93; ESI-LCMS:m/z 450 [M+H]⁺.

Example 20 Preparation of Compound (20a)

Preparation of (P20-1):

To a stirred suspension of P3-1 (20.0 g, 81.3 mmol), imidazole (15.9 g,234.0 mmol), PPh₃ (53.5 g, 203.3 mmol) and pyridine (90 mL) in anhydrousTHF (360 mL) was added dropwise a solution of I₂ (41.3 g, 162.6 mmol) inTHF (350 mL) at 0° C. After addition, the mixture was warmed to R.T. andstirred for 14 hours. The solution was quenched with aq. Na₂S₂O₃ (150mL) and extracted with EA. The organic layer was dried over Na₂SO₄ andconcentrated. The residue was purified on a silica gel column(DCM:MeOH=100:1 to 10:1) to afford P20-1 as a white solid (22.1 g,76.4%). ¹H NMR (CD₃OD, 400 MHz) δ 7.70 (d, J=8.0 Hz, 1H), 5.88 (dd,J₁=1.6 Hz, J₂=20.8 Hz, 1H), 5.71 (d, J=8.4 Hz, 1H), 5.24 (dd, J₁=2.0 Hz,J₂=5.2 Hz, 1H), 5.10 (dd, J₁=2.0 Hz, J₂=5.2 Hz 1H), 3.78-3.83 (m, 1H),3.61-3.65 (m, 1H), 3.44 (dd, J₁=J₂=6.0 Hz, 1H).

Preparation of (P20-2):

To a stirred solution of P20-1 (22.1 g, 62.1 mmol) in anhydrous THF (200mL) was added dropwise DBU (14.2 g, 93.1 mmol) in THF (50 mL) at 0° C.over 10 mins. The mixture was stirred at 60° C. for 6 hours. Thereaction was quenched with aq. NaHCO₃ (200 mL) and extracted with EA.The organic layer was washed with brine and dried over Na₂SO₄. Thesolvent was removed, and the residue was purified on a silica gel column(MeOH:DCM=1/100 to 1/30) to afford P20-2 as a white solid (8.7 g,61.5%). ¹H NMR (CD₃OD, 400 MHz) δ 7.51 (d, J=8.0 Hz, 1H), 6.05 (dd,J₁=1.2 Hz, J₂=17.2 Hz, 1H), 5.73 (d, J=8.0 Hz, 1H), 5.26 (dd, J₁=1.2 Hz,J₂=4.8 Hz, 1H), 5.13 (dd, J₁=1.2 Hz, J₂=4.8 Hz, 1H), 4.63 (dd, J₁=2.0Hz, J₂=3.2 Hz, 1H), 4.41 (dd, J₁=J₂=2.0 Hz, 1H).

Preparation of (P20-3):

To a stirred solution of P20-2 (3.2 g, 14.0 mmol) in anhydrous pyridine(10 mL) and DCM (100 mL) was added dropwise a solution of TBSCl (4.2 g,28.0 mmol) at 0° C. Stirring was continued at R.T. for 18 hours. Themixture was diluted with DCM. The organic layer was washed with brineand dried over Na₂SO₄. The solvent was removed, and the residue waspurified on a silica gel column (10% MeOH in DCM) to afford P20-3 as awhite solid (3.4 g, 70.8%).

Preparation of (P20-4):

To a stirred solution of NaHCO₃ in H₂O (250 mL) and acetone (200 mL) wasadded oxone (30.0×4 g) at 0° C. The mixture was warmed to R.T., and thedistillate was collected at −78° C. (120 mL) under slightly reducedpressure to give a solution of DMDO in acetone. To a stirred solution ofP20-3 (250.0 mg, 0.7 mmol) in DCM (20 mL) were added a DMDO (120 mL)solution at −40° C. and MgSO₄. The mixture was warmed to R.T. and thenstirred for 2 hours. The solution was filtrated, and the filtrate wasused for the next-step directly.

Preparation of (P20-5):

To a stirred solution of P20-4 (500.0 mg, 1.4 mmol) in anhydrous DCM (50mL) was added allyl-trimethyl-silane (760.0 mg, 6.7 mmol) and SnCl₄ (1.2g, 4.5 mmol) at −40° C. The mixture was warmed and stirred at 0° C. for1 hour. The reaction was quenched with saturated NaHCO₃ and extractedwith DCM. The organic layer was dried over Na₂SO₄ and concentrated. Theresidue was purified on a silica gel column (20-50% EA in PE) to giveP20-5 as a white foam (120 mg, 41%). ¹H NMR (CD₃OD, 400 MHz) δ 8.01 (d,J=8.4 Hz, 1H), 6.12 (dd, J₁=3.6 Hz, J₂=15.2 Hz, 1H), 5.87-5.96 (m, 1H),5.71 (d, J=8.4 Hz, 1H), 5.06-5.22 (m, 3H), 4.60 (dd, J₁=5.6 Hz, J₂=14.4Hz, 1H), 3.72 (d, J=11.6 Hz, 1H), 3.48 (d, J=11.6 Hz, 1H), 2.62-2.67 (m,1H), 2.23-2.29 (m, 1H); ESI-LCMS: m/z=422 [M+Na]⁺.

Preparation of (P20-6):

To a stirred solution of P20-5 (270.0 mg, 0.7 mmol) in dry DCM wereadded imidazole (400.0 mg, 5.9 mmol) and TBSCl (390.0 mg, 2.6 mmol) atR.T. The mixture was stirred at R.T. for 18 hours. The solution wasdiluted with EA. The solvent was washed with brine and dried overNa₂SO₄. The solvent was removed, and the residue was purified on asilica gel column (20-40% EA in PE) to afford compound P20-6 as a whitefoam (280 mg, 80.7%). ESI-LCMS: m/z 537 [M+Na]⁺.

Preparation of (P20-7):

To a stirred solution of P20-6 (280.0 mg, 0.5 mmol) in dry MeCN wereadded TPSCl (350.0 mg, 1.2 mmol), NEt₃ (400.0 mg, 4.0 mmol) and DMAP(270.0 mg, 2.2 mmol) at R.T. The mixture was stirred at R.T. for 18hours. The solution was quenched with ammonium. The organic layer waswashed with brine and dried over Na₂SO₄. The solvent was removed, andthe residue was purified by TLC (using EA) to afford compound P20-7 as awhite foam (240.0 mg, 85.7%). ESI-LCMS: m/z 514 [M+H]⁺.

Preparation of (P20-8):

To a stirred solution of P20-7 (270.0 mg, 0.5 mmol) in dry DCM wereadded AgNO₃ (1.5 g, 8.8 mmol), MMTrCl (450.0 mg, 1.5 mmol) and collidine(500.0 mg, 4.1 mmol) at R.T. The mixture was stirred at R.T. for 18hours. The solution was diluted with DCM. The organic layer was washedwith brine and dried over Na₂SO₄. The solvent was removed, and theresidue was purified on a silica gel column (20-40% EA in PE) to affordcompound P20-8 as a white foam (300 mg, 81.6%). ESI-LCMS: m/z 786[M+H]⁺.

Preparation of (20a):

To a stirred solution of P20-8 (170.0 mg, 0.3 mmol) in dry MeOH wasadded NH₄F (300.0 mg, 8.1 mmol), and the mixture was refluxed for 24hours. The solvent was removed under reduced pressure, and the residuewas purified on a silica gel column (2-5% MeOH in DCM) to give the crudeproduct. The crude product was further purified by RP HPLC (water and0.1% HCOOH in MeCN) to afford compound 20a as a white solid (47.0 mg,49.8%). ¹H NMR (CD₃OD, 400 MHz) δ 8.13 (d, J=8.4 Hz, 1H), 6.12 (dd,J₁=3.2 Hz, J₂=12.0 Hz, 1H), 5.87-5.97 (m, 2H), 4.98-5.14 (m, 3H), 4.45(dd, J₁=5.2 Hz, J₂=17.6 Hz, 1H), 3.71 (d, J=11.6 Hz, 1H), 3.54 (d,J=11.6 Hz, 1H), 2.54-2.59 (m, 1H), 2.33-2.39 (m, 1H); ESI-LCMS: m/z 286[M+H]⁺.

Example 21 Preparation of Compound (21a)

Preparation of (P21-1):

To a stirred solution of P20-8 (250.0 mg, 0.3 mmol) in MeOH was addedPd/C (500.0 mg), and the mixture was stirred under H₂ (balloon) for 18hours at R.T. The reaction was filtered, and the solvent removed underreduced pressure. The residue was purified by prep. TLC (30% EtOAc inPE) to afford P21-1 as a white foam (210.0 mg, 84.0%).

Preparation of (P21-2):

To a stirred solution of P21-1 (210.0 mg, 0.3 mmol) in dry THF was addedTBAF (1 mL, μmol), and the mixture was stirred at R.T. for 18 hours. Thesolvent was removed under reduced pressure, and the residue was purifiedby prep. TLC (30% EtOAc in PE) to give compound 21a as a white foam(111.2 mg, 74.6%). ¹H NMR (DMSO-d6, 400 MHz) δ 8.49 (s, 1H), 7.75 (d,J=6.8 Hz, 1H), 6.83-7.32 (m, 14H), 6.25 (d, J=7.6 Hz, 1H), 5.95 (dd,J₁=4.8 Hz, J₂=14.8 Hz, 1H), 5.48 (d, J=5.6 Hz, 1H), 4.86-5.15 (m, 2H),4.15-4.21 (m, 1H), 3.72 (s, 3H), 3.38-3.49 (m, 2H), 1.24-1.58 (m, 4H),0.84 (t, J=7.2 Hz, 3H); ESI-MS: m/z 560 [M+H]⁺.

Preparation of (P21):

Compound P21-2 (81 mg) was dissolved in a mixture (5 mL) of formic acid(80%) and water (20%). The resulting solution was stirred at R.T. for 3hours and then concentrated. The residue was co-evaporated withmethanol/toluene three times. Chromatography on silica gel with 5-12%methanol in DCM gave a mixture of two compounds, which was dissolved inmethanol with a drop of concentrated aqueous ammonia and concentrated.The residue was purified on silica gel with 5-12% methanol in DCM togive compound 21a (27 mg) as a white solid; ¹H NMR (CD₃OD, 400 MHz) δ8.05 (d, J=7.6 Hz, 1H), 6.06 (dd, J₁=2.8 Hz, J₂=16 Hz, 1H), 5.87 (d,J=7.6 Hz, 1H), 5.10 (dd, J=3.2, 5.2 Hz, 0.5H), 4.96 (dd, 3.2, 5.2 Hz,0.5H), 4.42 (dd, J=5.6, 17.2 Hz, 1H), 3.67 (dd, J=11.6, 76 Hz, 2H),1.70-1.79 (m, 1H), 1.31-1.61 (m, m, 3H), 0.94 (t, J=6.8 Hz, 3H). MS: m/z417 [M+2-methylheptylamine]⁺.

Example 22 Preparation of Compound (22a)

Preparation of (P22-1):

To a solution of P20-2 (5.23 g, 23.1 mmol) in anhydrous MeOH (50 mL) wasadded PbCO₃ (12.7 g, 46.3 mmol) at R.T. A solution of I₂ (11.7 g, 46.3mmol) in MeOH (10 mL) was then added dropwise at 0° C. The reactionmixture was stirred at R.T. for overnight. The reaction was quenchedwith Na₂S₂O₃ and dissolved in EA. The organic layer was dried overNa₂SO₄ and concentrated. The residue was purified by column(DCM/MeOH=100/1 to 20/1) to give P22-1 as a white solid (5.6 g, 71.8%).¹H NMR (CD₃OD, 400 MHz) δ 7.67 (d, J=8.0 Hz, 1H), 5.88 (dd, J₁=J₂=7.6Hz, 1H), 5.73 (d, J=8.0 Hz, 1H), 5.24 (dd, J₁=4.4 Hz, J₂=6.4 Hz, 1H),5.11 (dd, J₁=6.4 Hz, J₂=6.0 Hz, 1H); 4.65 (dd, J₁=20.0 Hz, J₂=20.4 Hz,1H), 3.67 (d, J=11.6 Hz, 1H), 3.54 (d, J=11.6 Hz, 1H), 3.43 (s, 3H).

Preparation of (P22-2):

To a stirred solution of P22-1 (5.6 g, 14.5 mmol) in anhydrous pyridine(20 mL) was added dropwise BzCl (2.9 g, 20.9 mmol) at 0° C. The mixturewas stirred at R.T. for 10 hours. The reaction was quenched with H₂O,and the solution was concentrated. The residue was dissolved in EA andwashed with saturated NaHCO₃. The organic layer was dried over Na₂SO₄and concentrated. The residue was purified on a silica gel column(20˜40% EA in PE) to give P22-2 as a white foam (4.9 g, 74.2%).

Preparation of (P22-3):

P22-2 (4.9 g, 10.0 mmol), BzONa (14.4 g, 100 mmol) and 15-crown-5 (22.0g, 100 mmol) were suspended in DMF (200 mL). The mixture was stirred at60-70° C. for 3 days. The precipitate was removed by filtration, and thefiltrate was diluted with EA. The solvent was washed with brine anddried over Na₂SO₄. The solvent was removed, and the residue was purifiedon a silica gel column (20-60% EA in PE) to afford P22-3 as a white foam(2.3 g, 47.9%).

Preparation of (P22-4):

P22-3 (2.3 g, 4.8 mmol), DMAP (1.2 g, 9.6 mmol), TPSCl (2.9 g, 9.6 mmol)and Et₃N (0.97 g, 9.6 mmol) were suspended in MeCN (10 mL). The mixturewas stirred at R.T. for 14 hours. NH₃ in THF (saturated at 0° C., 100mL) was added to the mixture, and the mixture stirred at R.T. for 2hours. The solvent was removed, and the residue was purified by column(DCM/MeOH=100:1 to 50:1) to give the crude product (1.2 g). The crudeproduct was dissolved in pyridine, and BzCl (0.42 g, 3.0 mmol) wasadded. The mixture was stirred at R.T. for 16 hours and quenched withwater. The solvent was removed, and the residue was purified on a silicagel column (PE:EA=2:1 to 1:1) to give P22-4 as a white foam (460 mg,31%).

Preparation of (22a):

P22-4 (0.46 g, 0.8 mmol) was dissolved in saturated methanolic ammonia(100 mL), and the mixture was stirred at R.T. for 14 hours. The solventwas removed, and the residue was dissolved in H₂O and washed with DCM.The aqueous phase was lyophilized and further purified by prep. HPLC(0.1% formic acid in water/acetonitrile) to give compound 22a as a whitesolid (145 mg, 78.9%). ¹H NMR (CD₃OD, 400 MHz) δ 7.88 (d, J=7.6 Hz, 1H),6.03 (d, J=18.4 Hz, 1H), 5.87 (d, J=7.6 Hz, 1H), 4.86-5.00 (m, 1H), 4.49(dd, J₁=23.2 Hz, J₂=22.8 Hz, 1H), 3.90 (d, J=12.0 Hz, 1H), 3.66 (d,J=12.0 Hz, 1H), 3.41 (s, 3H); ESI-MS: m/z 276 [M+H]⁺.

Example 23 Preparation of Compound (23a)

Preparation of (P23-2):

To a solution of P23-1 (3.1 g, 4.5 mmol) in DMF (30 mL) was addedanhydrous K₂CO₃ (1.24 g, 9.03 mmol) and PMBCl (1.40 g, 9.03 mmol). Themixture was stirred at ambient temperature overnight. The reaction wasquenched with water and extracted with EA. The organic layer wasconcentrated, and the residue was purified on a silica gel column(PE:EA=10:1 to 4:1) to give the intermediate as a white solid (2.36 g,74.8%). ¹H NMR (CDCl₃, 400 MHz) δ 7.29-7.88 (m, 23H), 6.83-6.98 (m, 6H),6.35-6.45 (m, 1H), 4.51-5.50 (m, 6H), 3.89-3.95 (m, 9H), 3.66-3.71 (m,2H), 3.03 (d, J=11.2 Hz, 1H), 1.21 (s, 9H), 0.89 (m, 9H), 0.01-0.11 (m,6H). The intermediate was used in the next step.

To a stirred solution of the intermediate (11.0 g, 10.47 mmol) inanhydrous THF (100 mL) was added TBAF (8.20 g, 31.42 mmol) at R.T., andthe mixture was stirred at R.T. for 5 hours. The solution was removed,and the residue was purified on a silica gel column (PE:EA=5:1 to 1:1)to give a second intermediate as a white solid (5.99 g, 82%).

To a stirred solution of the second intermediate (500 mg, 0.716 mmol) inanhydrous DMF (10 mL) was added NaH (51.5 mg, 2.14 mmol) and BnBr (365mg, 2.14 mmol) dropwise at 0° C. The mixture was stirred at R.T. forovernight. The solution was quenched with water and extracted with EA.The concentrated organic phase was purified on a silica gel column(PE:EA=10:1 to 4:1) to give a third intermediate as a white solid (496mg, 79%).

The third intermediate (2.5 g, 2.84 mmol) was dissolved in 80% HOAc (25mL) at R.T., and the mixture was stirred at R.T. for overnight. Thereaction was quenched with MeOH, and the solvent was removed. The crudewas purified on a silica gel column (PE:EA=5:1 to 1:1) to give P23-2 asa white solid (1.2 g, 73%).

Preparation of (P23-3):

To a stirred solution of DAST (1.39 g, 8.68 mmol) in anhydrous toluene(15 mL) was added dropwise a solution of P23-2 (1.0 g, 1.73 mmol) at−78° C. The mixture was stirred at −78° C. for 30 mins. The solution washeated to 60° C. gradually and then stirred overnight. The mixture waspoured into saturated Na₂CO₃ solution. The concentrated organic phasewas purified on a silica gel column (PE:EA=10:1 to 4:1) to give P23-3 asa white solid (449 mg, 45%). ¹H NMR (CD₃OD, 400 MHz) δ 7.87 (d, J=8.4Hz, 1H), 7.27-7.37 (m, 12H), 6.82-6.84 (m, 2H), 6.14 (dd, J=16.8, 2.0Hz, 1H), 5.18-5.50 (m, 4H), 4.96 (s, 2H), 4.45-4.88 (m, 7H), 3.67-3.89(m, 5H).

Preparation of (P23-4):

A mixture of P23-3 (1.20 g, 2.07 mmol) and CAN (3.41 g, 6.23 mmol) in asolution of MeCN:Water (3:1, 10 mL) was stirred at R.T. overnight. Brine(10 mL) was added, and the mixture was extracted with EA. The combinedorganic extracts were dried and evaporated under reduced pressure. Theresidue was purification by chromatography on silica gel (PE:EA=10:1 to2:1) to give P23-4 as a yellow solid (475 mg, 49.8%).

Preparation of (P23-5):

To a stirred solution of P23-4 (550 mg, 210 mmol) in anhydrous MeCN (10mL) were added TPSCl (725 mg, 2.40 mmol), DMAP (293 mg, 2.40 mmol) andTEA (242 mg, 2.40 mmol) at R.T., and the mixture was stirred at R.T.overnight. NH₄OH (25 mL) was added, and the mixture was stirred for 2hours. The solvent was removed, and the residue was purified on a silicagel column (PE:EA=8:1 to 2:1) to give P23-5 as a white solid (700 mgcrude). ¹H NMR (CD₃OD, 400 MHz) δ 7.86 (d, J=8.4 Hz, 1H), 7.27-7.36 (m,10H), 6.13 (dd, J₁=17.2 Hz, J₂=2.0 Hz, 1H), 5.48-5.53 (m, 1H), 5.11-5.26(m, 1H), 4.44-4.74 (m, 7H), 3.89 (dd, J₁=10.4 Hz, J₂=2.0 Hz, 1H), 3.69(dd, J₁=10.8 Hz, J₂=1.6 Hz, 1H).

Preparation of (P23-6):

To a stirred solution of P23-5 (1.0 g, 2.18 mmol) in anhydrous DCM (15mL) was added MMTrCl (2.02 g, 6.56 mmol) and AgNO₃ (1.11 g, 6.56 mmol)at R.T., and the mixture was stirred at R.T. overnight. The solid wasfiltered off and washed with DCM. The filtrate was washed with brine anddried over Na₂SO₄. The organic phase was concentrated, and the residuewas purified on a silica gel column (PE:EA=8:1 to 2:1) to give P23-6 asa white solid (520 mg, 41%).

Preparation of (P23-7):

To a stirred solution of P23-6 (520 mg, 0.713 mmol) in acetone wereadded ammonium formate (2.0 g, 31.7 mmol, in portions) and 10% palladiumon carbon (1.0 g). The mixture was refluxed for 12 hours. The catalystwas filtered off and washed with solvent. The filtrate was added EA andwashed with brine. The concentrated organic phase was purified by columnchromatography (DCM:MeOH=100:1 to 15:1) and prep. TLC to give P23-7 as awhite solid (270 mg, 69.0%). ¹H NMR (CD₃OD, 400 MHz) δ 8.54 (s, 1H),7.73 (d, J=7.6 Hz, 1H), 7.13-7.32 (m, 12H), 6.83 (d, J=8.4 Hz, 2H), 6.29(d, J=7.6 Hz, 1H), 5.99-6.04 (m, 1H), 5.82 (d, J=5.6 Hz, 1H), 5.39 (t,J=5.2 Hz, 1H), 5.09 (t, J=5.2 Hz, 1H), 4.32-4.58 (m, 3H), 3.54-3.72 (m,5H). ESI-MS: m/z 549.6 [M+H]⁺.

Preparation of (23a):

P23-7 (130 mg, 0.236 mmol) was dissolved in 80% HCOOH (20 mL) at R.T.,and the mixture was stirred at 50° C. for 12 hours. The solvent wasremoved, and the residue was co-evaporated with toluene twice. Theresidue was re-dissolved in MeOH (20 mL) at 60° C. and stiffing wascontinued for 48 hours. The solvent was removed, and the residue waspurified by column chromatography (DCM:MeOH=100:1 to 10:1) to givecompound 23a as a white solid (45 mg, 69.0%). ¹H NMR (CD₃OD, 400 MHz) δ8.00 (d, J=7.6 Hz, 1H), 6.13 (dd, J₁=16.0 Hz, J₂=4.0 Hz, 1H), 5.89 (d,J=7.6 Hz, 1H), 5.18-5.21 (m, 1H), 5.05-5.07 (m, 1H), 4.60 (s, 1H),4.51-4.57 (m, 2H), 3.84 (dd, J₁=12.0 Hz, J₂=2.0 Hz, 1H), 3.75 (dd,J₁=12.0 Hz, J₂=2.0 Hz, 1H). ESI-MS: m/z 277.8 [M+H]⁺, 554.8 [2M+H]⁺.

Example 24 Preparation of Compound (24a)

Preparation of (P24-2):

To a solution of P24-1 (30.0 g, 100.0 mmol) in pyridine (300 mL) wasadded BzCl (56.0 g, 400 mmol) at 25° C. The mixture was stirred at 25°C. for 15 hours. The mixture was concentrated and purified by columnchromatography (PE:EA=20:1 to 2:1) to give crude P24-2 (55.0 g, 81%).

Preparation of (P24-3):

P24-2 (55.0 g, 92 mmol) was dissolved in 80% HOAc aq. solution, and themixture was refluxed for 14 hours. The solvent was removed under reducedpressure, and the residue was co-evaporated with toluene. The residuewas purified on a silica gel column (PE/EA=4:1 to 2:1) to give P24-3 asa white solid (39.2 g, 83%).

Preparation of (P24-4):

P24-3 (39.2 g, 83 mmol) was dissolved in saturated methanolic ammonia,and the resulting solution was stirred at R.T. for 15 hours. The solventwas removed, and the residue was purified on a silica gel column(DCM/MeOH=50:1 to 20:1) to give P24-4 (21.0 g, 95.8%).

Preparation of (P24-5):

To a solution of P24-4 (21.0 g, 79.5 mmol) in pyridine (250 mL) wasadded DMTrCl (28.2 g, 83.5 mmol) at 0° C. The solution was stirred atR.T. for 15 hours. The reaction was quenched with MeOH and concentratedto dryness under reduced pressure. The residue was dissolved in EtOAcand washed with water. The organic layer was dried over Na₂SO₄ andconcentrated. The residue was dissolved in DCM (300 mL). Imidazole (13.6g, 200 mmol) and TBSCl (30.0 g, 200 mmol) were added. The reactionmixture was stirred at R.T. for 12 hours. The reaction mixture waswashed with NaHCO₃ and brine. The organic layer was dried over Na₂SO₄and concentrated. The residue (48.5 g, 79.5 mmol) was dissolved in 80%HOAc aq. solution (400 mL). The mixture was stirred at R.T. for 20hours. The mixture was diluted with EtOAc and washed with NaHCO₃solution and brine. The organic layer was dried over Na₂SO₄ and purifiedby silica gel column chromatography (1-2% MeOH in DCM) to give P24-5 asa white solid (21.0 g, 70%). ¹H NMR (400 MHz, MeOD) 87.83 (d, J=8.0 Hz,1H), 6.14 (dd, J₁=6.0 Hz, J₂=10.0 Hz, 1H), 5.73 (d, J=8.4 Hz, 1H),4.38-4.46 (m, 1H), 3.89-3.91 (m, 1H), 3.88 (dd, J₁=2.8 Hz, J₂=5.2 Hz,1H), 3.72 (dd, J₁=2.8 Hz, J₂=5.2 Hz, 1H), 0.93 (s, 9H), 0.15 (m, 6H).ESI-MS: m/z 379.1 [M+H]⁺.

Preparation of (P24-6):

To a solution of P24-5 (21.0 g, 55.6 mmol) in anhydrous CH₃CN (200 mL)was added IBX (17.1 g, 61.1 mmol) at R.T. The reaction mixture wasrefluxed for 1 hour and then cooled to 0° C. The precipitate wasfiltered off, and the filtrate was concentrated to give the aldehyde asa yellow solid (21.0 g, 55.6 mmol). To a solution of the aldehyde (21.0g, 55.6 mmol) in dioxane (200 mL) were added 37% CH₂O (22.2 mL, 222.4mmol) and 2N NaOH aq. solution (55.6 mL, 111.2 mmol). The mixture wasstirred at R.T. for 2 hours and then neutralized with AcOH to pH=7. Tothe reaction were added EtOH (50 mL) and NaBH₄ (12.7 g, 333.6 mmol). Themixture was stirred at R.T. for 30 mins. The reaction was quenched withsaturated aq. NH₄Cl. extracted with EA. The organic layer was dried overNa₂SO₄ and concentrated. The residue was purified by silica gel columnchromatography (1-3% MeOH in DCM) to give P24-6 as a white solid (13.5g, 59.5%).

Preparation of (P24-7):

To a solution of P24-6 (13.5 g, 33.1 mmol) in DCM (100 mL) were addedpyridine (20 mL) and DMTrCl (11.2 g, 33.1 mmol) at 0° C. The solutionwas stirred at 25° C. for 3 hours, and then treated with MeOH (30 mL).The solvent was removed, and the residue was purified by silica gelcolumn chromatography (DCM:MeOH=300:1 to 100:1) to give a residue. Theresidue was dissolved in anhydrous pyridine (150 mL) and TBDPSCl (16.5g, 60 mmol) and AgNO₃ (10.2 g, 60 mmol) were added. The mixture wasstirred at 25° C. for 15 hours, and then filtered and concentrated. Themixture was dissolved in EtOAc and washed with brine. The organic layerwas dried over Na₂SO₄. Purified by silica gel column chromatography(DCM:MeOH=300:1 to 100:1) gave the product as a yellow solid (16.2 g,85.3%). The solid was dissolved in 80% HOAc aq. solution (400 mL). Themixture was stirred at R.T. for 15 hours. The mixture was diluted withEtOAc and washed with NaHCO₃ solution and brine. The organic layer wasdried over Na₂SO₄ and purified by silica gel column chromatography(DCM:MeOH=200:1 to 50:1) to give P24-7 as a white solid (9.5 g, 86.5%).¹H NMR (CD₃OD, 400 MHz) δ 7.39-7.70 (m, 11H), 6.34-6.38 (m, 1H), 5.12(d, J=8.0 Hz, 1H), 4.79 (dd, J₁=10.0 Hz, J₂=16.0 Hz, 1H), 4.14 (dd,J₁=1.6 Hz, J₂=11.6 Hz, 1H), 3.48-3.84 (m, 2H), 3.49 (dd, J₁=1.6 Hz,J₂=11.6 Hz, 1H), 1.12 (s, 9H), 0.92 (s, 9H), 0.16 (s, 6H).

Preparation of (P24-8):

To a solution of P24-7 (6.0 g, 9.3 mmol) in anhydrous DCM (80 mL) wasadded Dess-Martin periodinane (7.9 g, 18.6 mmol) at 0° C. undernitrogen. The reaction was stirred at R.T. for 1 hour. The solvent wasremoved in vacuo, and the residue was triturated with diethyl ether (50mL). The mixture was filtered through a pad of MgSO₄, and the organicsolvent was stirred with an equal volume of Na₂S₂O₃.5H₂O in saturatedNaHCO₃ (50 mL) until the organic layer became clear (approx. 10 min).The organic layer was separated, washed with brine, and dried overMgSO₄. After concentration in vacuo, P24-8 was obtained as a red solid(5.8 g. 98%).

Preparation of (P24-9):

To a mixture of methyltriphenylphosphonium bromide (9.6 g, 27.0 mmol) inanhydrous THF (60 mL) was added n-BuLi (10.8 mL, 27.0 mmol) at −70° C.under nitrogen. The reaction was stirred at 0° C. for 30 mins. Asolution of P24-8 (5.8 g, 9.0 mmol) in anhydrous THF (20 mL) was addeddropwise at 0° C. under nitrogen. The reaction was stirred at R.T. for12 hours. The reaction was quenched with NH₄Cl and extracted with EtOAc.The organic layer was separated, dried and concentrated, and the residuewas purified by silica gel column chromatography (DCM:MeOH=300:1 to100:1) to give P24-9 as a white solid (3.0 g, 51%).

Preparation of (P24-10):

To a solution of P24-9 (2.9 g, 4.5 mmol) in anhydrous MeOH (20 mL) wasadded Pd/C (1.4 g) at 25° C. under hydrogen atmosphere. The mixture wasstirred at 25° C. for 1 hour. The solution was filtered, evaporated todryness and purified on a silica gel column (DCM:MeOH=300:1 to 100:1) togive P24-10 as a white solid (2.3 g, 79.3%).

Preparation of (P24-11):

To a solution of P24-10 (1.0 g, 1.55 mmol) in anhydrous CH₃CN (20 mL)were added TPSCl (940 mg, 3.1 mmol), DMAP (380 mg, 3.1 mmol) and NEt₃(470 mg, 4.6 mmol) at R.T. The reaction was stirred at R.T. for 5 hours.NH₄OH (8 mL) was added, and the reaction was stirred for 1 hour. Themixture was diluted with DCM (150 mL) and washed with water, 0.1M HCland saturated aq. NaHCO₃. The solvent was removed, and the residue waspurified by silica gel column chromatography (PE:EA=10:1 to 1:1) to givethe crude product as a yellow solid (900 mg, 90%). To a solution of thecrude product in DCM (10 mL) were added MMTrCl (930 mg, 3.0 mmol), AgNO₃(510 mg, 3.0 mmol) and colliding (720 mg, 6.0 mmol) at R.T. The reactionwas stirred for 12 hours at R.T. The reaction was filtered, concentratedand purified by silica gel column chromatography (DCM:MeOH=200:1 to50:1) to give P24-11 as a yellow solid (1.1 g, 77.6%).

Preparation of (P24-12):

To a solution of P24-11 (1.1 g, 1.2 mmol) in MeOH (40 mL) was added NH₄F(1.0 g, 30 mmol) at 25° C. and stirred at 70° C. for 15 hours. Thesolution was filtered and evaporated to dryness, and the residue waspurified by silica gel column (DCM:MeOH=200:1 to 20:1) to give P24-12 asa white solid (450 mg, 66.6%). ¹H NMR (400 MHz, MeOD) 88.58 (s, 1H),7.62 (d, J=7.6 Hz, 1H), 7.13-7.30 (m, 12H), 6.83-6.85 (m, 2H), 6.29 (d,J=7.6 Hz, 1H), 6.18 (d, J=6.0 Hz, 1H), 5.94 (t, J=8.0 Hz, 1H), 5.22 (t,J=5.2 Hz, 1H), 4.28-4.37 (m, 1H), 3.72 (s, 3H), 3.57-3.62 (m, 1H),1.39-1.60 (m, 2H), 0.79-0.84 (m, 3H). ESI-LCMS: m/z 563.6 [M+H]⁺.

Preparation of (24a):

P24-12 (250 mg, 0.44 mmol) was dissolved in 80% HCOOH in H₂O (6.0 g) at25° C. The mixture was stirred at 35° C. for 15 hours. The solution wasevaporated to dryness, dissolved in MeOH (30 mL) and stirred at 60° C.for 12 hours. The solution was evaporated to dryness and purified bysilica gel column chromatography (DCM:MeOH=100:1 to 100:1) to givecompound 24a as a white solid (125.6 mg, 97%). ¹H NMR (400 MHz, MeOD)87.91 (d, J=7.6 Hz, 1H), 6.19 (t, J=7.6 Hz, 1H), 5.90 (d, J=7.2 Hz, 1H),4.47 (t, J=13.6 Hz, 1H), 3.67 (d, J=12.0 Hz, 1H), 3.52 (d, J=12.0 Hz,1H), 1.73-1.82 (m, 1H), 1.53-1.63 (m, 1H), 095 (t, J=7.6 Hz, 3H).ESI-LCMS: m/z 291.9 [M+H]⁺.

Example 25 Preparation of Compound (25a)

Preparation of (P25-2):

To a solution of P25-1 (20.0 g, 70.16 mmol) in anhydrous pyridine (200mL) was added imidazole (19.08 g, 280.7 mmol) and TBSCl (42.10 g, 280.7mmol) at 25° C. The solution was stirred at 25° C. for 15 hours, andthen concentrated to dryness under reduced pressure. The residue waswashed with EtOAc to give the crude product as a white solid (36.4 g).The crude product was dissolved in THF (150 mL) and H₂O (100 mL), andthen HOAc (300 mL) was added. The solution was stirred at 80° C. for 13hours. The reaction was cooled to R.T., and the mixture was concentratedto dryness under reduced pressure. The residue was dissolved washed withEtOAc and dried to give P25-2 as a white solid (31.2 g, 60.9%).

Preparation of (P25-3):

To a stirred solution of P25-2 (31.2 g, 78.2 mmol) in anhydrous pyridine(300 mL) was added Ac₂O (11.96 g, 117.3 mmol). The mixture was stirredat 25° C. for 18 hours. MMTrCl (72.3 g, 234.6 mmol) and AgNO₃ (39.9 g,234.6 mmol) were then added. The solution was stirred at 25° C. for 15hours. And H₂O was added to quench the reaction. The solution wasconcentrated to dryness under reduced pressure. The residue wasdissolved in EtOAc and washed with water. The organic layer was driedover Na₂SO₄ and filtered. The filtrate was concentrated in vacuo to givea residue. The residue was purified by silica gel (DCM:MeOH=200:1 to50:1) to give the product. The product was dissolved in NH₃/MeOH (300mL), and the mixture was stirred at 25° C. for 20 hours. The solvent wasremoved, and the residue was purified on a silica gel column(DCM:MeOH=100:1 to 50:1) to give P25-3 as a yellow solid (28.6 g,86.5%). ¹H NMR (400 MHz, MeOD) 88.01 (s, 1H), 7.23-7.35 (m, 12H),6.85-6.87 (m, 2H), 5.60 (dd, J₁=11.2 Hz, J₂=5.6 Hz, 1H), 4.78-4.94 (m,1H), 4.44 (dd, J₁=8.0 Hz, J₂=4.8 Hz, 1H), 3.78 (s, 3H), 3.60-3.63 (m,1H), 3.50 (dd, J₁=32.0 Hz, J₂=12.0 Hz, 2H), 3.32 (s, 3H), 0.94 (s, 9H),0.12-0.14 (m, 6H).

Preparation of (P25-4):

To a solution of P25-3 (7.24 g, 10.79 mmol) in anhydrous CH₃CN (100 mL)was added IBX (3.93 g, 14.03 mmol) at 20° C. The reaction mixture wasrefluxed at 90° C. for 1 hour. The reaction was filtered, and thefiltrate was concentrated to give the aldehyde as a yellow solid (7.1g). To a solution of the aldehyde (7.1 g, 10.6 mmol) in dioxane (80 mL)was added 37% CH₂O (4.2 mL, 42.4 mmol) and 2N NaOH aq. solution (8.0 mL,15.9 mmol). The mixture was stirred at 25° C. for 2 hours and thenneutralized with AcOH to pH=7. To reaction was added EtOH (30 mL) andNaBH₄ (2.4 g, 63.6 mmol), the reaction was then stirred for 30 mins. Themixture was quenched with saturated aq. NH₄Cl. The mixture was extractedwith EA, and the organic layer was dried over Na₂SO₄. The solvent wasremoved, and the residue was purified by silica gel columnchromatography (DCM:MeOH=200:1 to 50:1) to give P25-4 as a yellow solid(4.86 g, 65.4%).

Preparation of (P25-5):

To a solution of P25-4 (3.8 g, 5.4 mmol) in DCM (40 mL) were addedpyridine (10 mL) and DMTrCl (1.8 g, 5.4 mmol) at 0° C. The solution wasstirred at 25° C. for 1 hour. The reaction mixture was treated with MeOH(15 mL) and concentrated. The residue was purified by silica gel columnchromatography (DCM:MeOH=200:1 to 50:1) to give the mono-DMTr protectedintermediate as a yellow solid (3.6 g, 66.4%). To a solution of theintermediate in anhydrous pyridine (30 mL) were added TBDPSCl (2.96 g,10.8 mmol) and AgNO₃ (1.84 g, 10.8 mmol). The mixture was stirred at 25°C. for 15 hours. The mixture was filtered and concentrated, and thendissolved in EtOAc and washed with brine. The organic layer was driedover Na₂SO₄, and then concentrated. The residue was purified by silicagel column chromatography (DCM:MeOH=200:1 to 50:1) to give the pureintermediate as a white solid (3.8 g, 85.1%). To a solution of theintermediate (3.6 g, 2.9 mmol) in anhydrous DCM (50 mL) was addedCl₂CHCOOH (1.8 mL) in anhydrous DCM (18 mL) at −78° C. The mixture wasstirred at −10° C. for 30 mins. The mixture was quenched with saturatedaq. NaHCO₃ and extracted with DCM. The organic layer was dried overNa₂SO₄, and then purified by silica gel column chromatography(DCM:MeOH=200:1 to 50:1) to give P25-5 as a white solid (2.2 g, 80.7%).

Preparation of (P25-6):

P25-5 (2.2 g, 2.3 mol) was added to a suspension of Dess-Martinperiodinane (2.5 g, 5.8 mol) in anhydrous CH₂Cl₂ (30 mL) at 25° C. Themixture was stirred at 25° C. for 4 hours. The solvent was removed invacuo, and the residue triturated with diethyl ether (30 mL). Themixture was filtered through a pad of MgSO₄. The organic solvent wasstirred with an equal volume of Na₂S₂O₃.5H₂O in saturated NaHCO₃ (30 mL)until the organic layer became clear (approx. 10 min). The organic layerwas separated, washed with brine, and dried over MgSO₄. The solvent wasremoved in vacuo to give P25-6 as a yellow solid (2.1 g, 95%).

Preparation of (P25-7):

To a stirred solution of methyl-triphenyl-phosphonium bromide (2.3 g,6.6 mmol) in anhydrous THF (30 mL) was added dropwise n-BuLi (2.6 mL,6.6 mmol, 2.5 M in THF) at −78° C. over 1 minute. Stirring was continuedat 0° C. for 1 hour. P25-6 (2.1 g, 2.2 mmol) was added to the mixture,and then stirred at 25° C. for 15 hours. The reaction was quenched withsaturated NH₄Cl (50 mL). The mixture was extracted with EtOAc. Thecombined organic phase was dried with Na₂SO₄, filtered and evaporated todryness to give a light yellow oil. The oil was purified by columnchromatography (DCM:MeOH=200:1 to 50:1) to give P25-7 as a white solid(1.6 g, 76%).

Preparation of (P25-8):

To a solution of P25-7 (1.6 g, 1.7 mmol) in MeOH (50 mL) was added NH₄F(1.5 g, 40 mmol), and the mixture was stirred at 70° C. for 15 hours.The solution was filtered and evaporated to dryness. The residue waspurified by silica gel column (DCM:MeOH=200:1 to 20:1) to give P25-8 asa white solid (450 mg, 49%). ¹H NMR (400 MHz, MeOD) 87.95 (s, 1H),7.21-7.33 (m, 12H), 6.82-6.84 (m, 2H), 5.92 (dd, J₁=11.2 Hz, J₂=17.6 Hz,1H), 5.55-5.59 (m, 1H), 5.18-5.31 (m, 2H), 4.54-4.68 (m, 1H), 4.26-4.33(m, 1H), 3.76 (s, 3H), 3.43 (dd, J₁=12.4 Hz, J₂=36.4 Hz, 2H). ESI-LCMS:m/z 584.1 [M+H]⁺.

Preparation of (25a):

P25-8 (130 mg, 0.22 mmol) was dissolved in 80% HCOOH and the mixture wasstirred at 25° C. for 1 hour. Then the solution was evaporated todryness. The residue was dissolved in MeOH (30 mL) and stirred at 60° C.for 12 hours. Then the solution was evaporated to dryness, and theresidue was washed by EtOAc to give P25 as a white solid (52.3 mg, 76%).¹H NMR (400 MHz, MeOD) δ 8.03 (s, 1H), 6.17 (dd, J₁=3.2 Hz, J₂=16.8 Hz,1H), 6.03 (dd, J₁=11.2 Hz, J₂=17.2 Hz, 1H), 5.50 (dd, J₁=1.6 Hz, J₂=17.2Hz, 1H), 5.23-5.38 (m, 2H), 4.76 (dd, J₁=4.8 Hz, J₂=18.0 Hz, 1H), 3.60(dd, J₁=12.0 Hz, J₂=44.8 Hz, 2H). ESI-MS: m/z 334.1 [M+Na]⁺.

Example 26 Preparation of Compound (26a)

Preparation of (P26-1):

To a stirred solution of P25-6 (2.1 g, 2.2 mmol) in pyridine was addedHONH₂HCl (0.61 g, 8.8 mmol) at 25° C. The mixture was stirred at 25° C.for 2 hours. The mixture was concentrated, and the residue was purifiedby column chromatography (DCM:MeOH=200:1 to 50:1) to give P26-1 as awhite solid (1.8 g, 83%).

Preparation of (P26-2):

To a stirred solution of P26-1 (1.4 g, 1.47 mmol) in DCM were added TEA(0.44 g, 4.4 mmol) and methanesulfonyl chloride (0.34 g, 2.9 mmol) at 0°C. The mixture was stirred at 25° C. for 1 hour. The mixture wasquenched with saturated aq. NaHCO₃ and extracted with DCM. The organicphase was dried with Na₂SO₄, filtered and evaporated. The residue waspurified by column chromatography (DCM:MeOH=200:1 to 50:1) to give P26-2as a white solid (1.1 g, 79%).

Preparation of (P26-3):

To a solution of P26-2 (1.1 g, 1.18 mmol) in MeOH (50 mL) was added NH₄F(1.5 g, 40 mmol), and the mixture was stirred at 70° C. for 15 hours.The solution was filtered and evaporated to dryness. The residue waspurified by silica gel column (DCM:MeOH=200:1 to 20:1) to give P26-3 asa white solid (400 mg, 71%). ¹H NMR (400 MHz, MeOD) δ 7.80 (s, 1H),7.20-7.32 (m, 12H), 6.86-6.88 (m, 2H), 5.82 (dd, J₁=2.0 Hz, J₂=20.0 Hz,1H), 4.51-4.66 (m, 1H), 3.94 (dd, J₁=5.2 Hz, J₂=20.8 Hz, 1H), 3.78 (s,3H), 3.56 (dd, J₁=12.4 Hz, J₂=42.0 Hz, 2H). ESI-LCMS: m/z 583.1 [M+H]⁺.

Preparation of (26a):

P26-3 (200 mg, 0.34 mmol) was dissolved in 80% HCOOH aq. solution. Themixture was stirred at 25° C. for 1 hour. The solution was evaporated todryness, dissolved in MeOH (30 mL) and stirred at 60° C. for 12 hours.The solvent was removed, and the residue was washed by EtOAc to givecompound 26a as a white solid (100.4 mg, 95%). ¹H NMR (400 MHz, MeOD)87.90 (s, 1H), 6.34 (dd, J₁=2.0 Hz, J₂=19.6 Hz, 1H), 5.49 (ddd, J₁=1.6Hz, J₂=4.4 Hz, J₃=52.4 Hz, 1H), 5.01 (dd, J₁=4.8 Hz, J₂=20.8 Hz, 1H),3.93 (dd, J₁=12.4 Hz, J₂=44.8 Hz, 2H). ESI-MS: m/z 311.1 [M+H]⁺.

Example 27 Preparation of Compound (27a)

Preparation of (P27-1):

To a stirred solution of chloromethyl-triphenyl-phosphonium chloride(1.9 g, 5.4 mmol) in anhydrous THF (30 mL) was added dropwise n-BuLi(2.16 mL, 5.4 mmol, 2.5 M in THF) at −78° C. over 10 mins. Stirring wascontinued at −78° C. for 2 hours. P25-6 (1.7 g, 1.8 mmol) was added, andthe mixture and stirred at 25° C. for 15 hours. The reaction wasquenched with saturated NH₄Cl (50 mL). The mixture was extracted withEtOAc. The combined organic phase was dried with Na₂SO₄, filtered andevaporated to dryness to give a light yellow oil. The oil was purifiedby column chromatography (DCM:MeOH=200:1 to 50:1) to give P27-1 as awhite solid (1.2 g, 70%).

Preparation of (P27-2):

To a stirred solution of P27-1 (1.2 g, 1.3 mmol) in anhydrous THF (20mL) was added dropwise n-BuLi (8.0 mL, 20 mmol, 2.5 M in THF) at −78° C.over 10 minutes. Stirring was continued at −78° C. for 4 hours. Thereaction was quenched with saturated NH₄Cl (50 mL). The mixture wasextracted with EtOAc (50×2 mL). The combined organic phase was driedover Na₂SO₄, filtered and evaporated to dryness. The residue waspurified by column chromatography (DCM:MeOH=200:1 to 50:1) to give P27-2as a white solid (1.0 g, 83%).

Preparation of (P27-3):

To a solution of P27-2 (1.0 g, 1.1 mmol) in MeOH (40 mL) was added NH₄F(1.5 g, 40 mmol), and the mixture was stirred at 70° C. for 25 hours.The solution was filtered, and the filtrate was evaporated to dryness.The residue was purified on a silica gel column (DCM:MeOH=200:1 to 20:1)to give P27-3 as a white solid (240 mg, 38%). ¹H NMR (400 MHz, MeOD) δ7.85 (s, 1H), 7.21-7.31 (m, 12H), 6.84-6.87 (m, 2H), 5.67 (dd, J₁=1.6Hz, J₂=19.2 Hz, 1H), 4.47-4.62 (m, 1H), 3.94 (dd, J₁=5.2 Hz, J₂=22.4 Hz,1H), 3.77 (s, 3H), 3.56 (dd, J₁=12.4 Hz, J₂=47.2 Hz, 2H), 3.04 (s, 1H).ESI-LCMS: m/z 582.1 [M+H]⁺.

Preparation of (27a):

P27-3 (130 mg, 0.22 mmol) was dissolved in 80% HCOOH aq. solution. Themixture was stirred at 25° C. for 1 hour. The solution was evaporated todryness. The residue was dissolved in MeOH (30 mL) and stirred at 60° C.for 12 hours. The solvent was removed, and the residue was washed withEtOAc to give compound 27a as a white solid (43.0 mg, 63%). ¹H NMR (400MHz, MeOD) 87.95 (s, 1H), 6.22 (dd, J₁=2.4 Hz, J₂=18.4 Hz, 1H), 5.49(ddd, J₁=2.0 Hz, J₂=4.8 Hz, J₃=53.2 Hz, 1H), 4.77 (dd, J₁=5.2 Hz,J₂=20.0 Hz, 1H), 3.79 (dd, J₁=12.4 Hz, J₂=46.8 Hz, 2H), 3.12 (s, 3H).ESI-MS: m/z 310.1 [M+H]⁺.

Example 28 Preparation of Compound (28a)

Preparation of (P28-1):

To a stirred solution of P25-1 (5.7 g. 20 mmol) in anhydrous pyridine(20 mL) was added dropwise Ac₂O (5.8 mL, 60 mmol) at 0° C. The mixturewas stirred at R.T. for 10 hours. AgNO3 (8.5 g, 50 mmol) and MMTrCl(15.5 g, 50 mmol) were added. The mixture was stirred at R.T. for 10hours. The solution was quenched with saturated NaHCO₃ and extractedwith EA. The organic layer was dried over Na₂SO₄ and concentrated. Theresidue was purified on a silica gel column (DCM/MeOH=100:1 to 50:1) toafford the intermediate as a light yellow solid (12.1 g, 93.4%). Thesolid was treated with saturated NH₃ in MeOH at R.T. for 14 hours. Thesolvent was removed, and the residue was purified by silica gel columnchromatography (DCM/MeOH=80:1 to 30:1) to afford P28-1 as a white solid(9.2 g, 87.5%).

Preparation of (P28-2):

To a stirred solution of P28-1 (9.2 g, 16.5 mmol) in dry THF (300 mL)were added imidazole (9.0 g, 132 mmol) and PPh₃ (34.8 g, 132 mmol). Asolution of I₂ (26.0 g, 103 mmol) in THF (100 mL) was added dropwiseunder N₂ at 0° C. The mixture was stirred at R.T. for 18 hours. Thereaction was quenched with Na₂S₂O₃ solution, and the mixture wasextracted with EtOAc. The organic layer was dried over Na₂SO₄ andconcentrated. The residue was purified by silica gel columnchromatography (DCM/MeOH=80:1 to 30:1) to give P28-2 as a light yellowsolid (10.3 g, 93.4%).

Preparation of (P28-3):

To a stirred solution of P28-2 (10.2 g, 15.3 mmol) in dry THF (300 mL)was added DBU (4.7 g, 30.1 mmol). The mixture was stirred at 60° C. for8 hours. The solution was diluted with NaHCO₃ solution and extractedwith EtOAc. The organic layer was dried over Na₂SO₄ and concentrated.The residue was purified by silica gel column chromatography(PE/EtOAc=3:1 to 1:3) to afford P28-3 as a light yellow foam (6.2 g,75.6%). ¹H NMR (CD₃OD, 400 MHz) δ 7.71 (s, 1H), 7.23-7.76 (m, 14H), 6.74(d, J=0.8 Hz, 2H), 5.83-5.88 (dd, J₁=2.8 Hz, J₂=16.0 Hz, 2H), 4.57-4.89(m, 2H), 4.30-4.35 (m, 1H), 4.79 (s, 3H). ESI-MS: m/z 540 [M+H]⁺.

Preparation of (P28-4):

To a stirred solution of P28-4 (5.42 g, 10 mmol) in anhydrous CH₃OH (100mL) were added PbCO₃ (13.7 g, 53.1 mmol) followed by a solution of I₂(12.3 g, 48.9 mmol) in CH₃OH (300 mL) at 0° C. The mixture was stirredat R.T. for 10 hours. The solution was quenched with a Na₂S₂O₃ solutionand extracted with DCM. The organic layer was washed with NaHCO₃solution, dried over Na₂SO₄ and concentrated. The residue was purifiedby pre-HPLC (MeCN and 0.1% HCOOH in water) to give the pure product as awhite foam (2.4 g, 34%). The product was dissolved in dry pyridine (20mL) and BzCl (723 mg, 5.2 mmol) was added dropwise at 0° C. The mixturewas stirred at 0° C. for 1 hour. The solution was quenched with NaHCO₃solution, and extracted with EtOAc. The organic layer was dried overNa₂SO₄ and concentrated. The residue was purified by silica gel columnchromatography (PE/EtOAc=5:1 to :1) to afford P28-4 as a white solid(2.1 g, 77.1%).

Preparation of (P28-5):

P28-4 (2.0 g, 2.5 mmol), BzONa (3.6 g, 25 mmol) and 15-crown-5 (5.5 g,25 mmol) were suspended in DMF (50 mL). The mixture was stirred at110-125° C. for 5 days. The precipitate was removed by filtration, andthe filtrate was diluted with EA. The solution was washed with brine anddried over Na₂SO₄. The solvent was removed, and the residue was purifiedon a silica gel column (PE/EA=10/1 to 2/1) to afford crude P28-5 as alight yellow foam (1.6 g, 80%).

Preparation of (P28-6):

P28-5 (1.6 g, 2.0 mmol) was dissolved in methanolic ammonia (100 mL,saturated), and the mixture was stirred at R.T. for 20 hours. Thesolvent was removed, and the residue was purified on a silica gel column(DCM/MeOH=100:1 to 20:1) to give P28-6 as a white solid (410 mg, 34.9%).¹H NMR (400 MHz, MeOD) δ 7.84 (s, 1H), 7.20-7.33 (m, 12H), 6.83-6.86 (m,2H), 5.64 (dd, J₁=1.6 Hz, J₂=18.4 Hz, 1H), 4.46-4.62 (m, 1H), 4.08 (dd,J₁=6.0 Hz, J₂=22.0 Hz, 1H), 3.76 (s, 3H), 3.58 (dd, J₁=12.4 Hz, J₂=30.4Hz, 2H), 3.31 (s, 3H). ESI-LCMS: m/z 588.1 [M+H]⁺.

Preparation of (28a):

P28-8 (200 mg, 0.34 mmol) was dissolved in 80% HCOOH and the mixture wasstirred at 25° C. for 1 hour. The solution was evaporated to dryness,and the residue was dissolved in MeOH (30 mL) and stirred at 60° C. for12 hours. The solvent was removed, and the residue washed with EtOAc togive compound 28a as a white solid (46.1 mg, 43%). ¹H NMR (400 MHz,MeOD) 87.92 (s, 1H), 6.22 (dd, J₁=1.6 Hz, J₂=18.8 Hz, 1H), 5.25 (ddd,J₁=1.6 Hz, J₂=6.0 Hz, J₃=54.0 Hz, 1H), 4.89-4.91 (m, 1H), 3.87 (d,J=11.6 Hz, 1H), 3.67 (d, J=12.0 Hz, 1H), 3.44 (s, 3H). ESI-MS: m/z 316.1[M+H]⁺.

Example 29 Preparation of Compound (29a)

DEAD (40% in toluene, 0.15 mL, 0.33 mmol) was added to a stirredsolution of triphenylphosphine (78 mg, 0.3 mmol) in anhydrous1,4-dioxane (0.5 mL) at 0° C. under argon. The mixture was warmed up toR.T. and compound 10a (26 mg, 0.1 mmol) andbis(pivaloyloxymethyl)phosphate (98 mg, 0.3 mmol) were added. Theresulting mixture was stirred at 65° C. for 3 days.Diisopropylethylamine (50 μL) was added, and the mixture was stirred at70° C. for 3 days. Another reaction of the same scale was conductedseparately. The two reaction mixtures were combined and concentrated.Chromatography on silica gel with 5-10% methanol in DCM gave the desiredproduct (20 mg) with a minor impurity. A second chromatography on silicagel, followed by RP HPLC with acetonitrile/water, gave the compound (2.8mg) as a colorless residue; ¹H NMR (CD₃OD, 400 MHz) δ 7.65 (d, J=8.0 Hz,1H), 5.94 (dd, J₁=2.4 Hz, J₂=18.8 Hz, 1H), 5.70 (d, J=8.0 Hz, 1H), 5.69(d, J=0.8 Hz, 1H), 5.68 (s, 1H), 5.654 (d, J=1.2 Hz, 1H), 5.650 (s, 1H),5.21 (dd, J=2.0, 5.2 Hz, 0.5H), 5.07 (dd, 2.0, 5.2 Hz, 0.5H), 4.42 (dd,J=5.6, 20.8 Hz, 1H), 4.14 (m, 2H), 1.223 (s, 9H), 1.220 (m, 9H); ³¹P NMR(CD₃OD) 4.92 (s); MS: m/z 698 [M+2-methylheptylamine]⁺.

Example 30 Preparation of Compound (30a)

Preparation of (1-2):

To a solution of 1-1 (313 mg; 0.55 mmol) in THF (8 mL) under Ar wasadded a solution of triethylammonium bis(POM)phosphate in THF (preparedfrom bis(POM)phosphate (215 mg; 1.2 equiv), THF (2 mL) and Et₃N (0.1 mL;1.3 equiv)). The resulting mixture cooled in an ice-bath.Diisopropylethyl amine (0.38 mL; 4 equiv) was added. BOP-Cl (280 mg; 2equiv) and 3-nitro-1,2,4-triazole (125 mg; 2 equiv) was then added. Thereaction mixture was stirred at 0° C. for 90 mins. The mixture wasdiluted with CH₂Cl₂ (60 mL) and washed with saturated aq. NaHCO₃ (2×10mL) and brine. The combined aqueous layers were back extracted withCH₂Cl₂ (˜20 mL). The combined organic extract was dried (Na₂SO₄) andevaporated. The residue purified on silica (25 g column) withCH₂Cl₂/i-PrOH solvent system (2-10% gradient). Yield: 140 mg (27%).

Preparation of (30a):

A solution of 1-2 (110 mg; 0.13 mmol) in 80% aq. formic acid was heatedat 35-37° C. for 3 hours. The mixture was evaporated to give an oilyresidue. The residue was co-evaporated 2 times with toluene.Purification on a silica gel column (10 g) with CH₂Cl₂/MeOH solventsystem (4-10% gradient) to afford compound 30a (46 mg, 59% yield).³¹P-NMR (DMSO-d₆): δ −4.45. MS: m/z 646 (M+46-1).

Example 31 Preparation of Compound (31a)

Preparation of (2-2):

To a solution of 2-1 (370 mg; 0.64 mmol) in THF (10 mL) under Ar wasadded triethylammonium bis(POM)phosphate (330 mg; 1.2 equiv). Themixture cooled in ice-bath, and diisopropylethyl amine (0.42 mL; 4equiv) was added. BOP-Cl (305 mg; 2 equiv) and 3-nitro-1,2,4-triazole(137 mg; 2 equiv) was then added. The reaction mixture was stirred at 0°C. for 90 mins. The mixture was diluted with CH₂Cl₂ (50 mL) and washedwith saturated aq. NaHCO₃ (2×10 mL) and brine. The combined aqueouslayers were back extracted with CH₂Cl₂ (˜20 mL). The combined organicextract was dried (Na₂SO₄), evaporated, and the residue purified onsilica (25 g column) with CH₂Cl₂/i-PrOH solvent system (2-10% gradient).Yield: 154 mg (27%).

Preparation of (31a):

A solution of 2-2 (68 mg; 0.08 mmol) in 80% aq. formic acid was stirredat R.T. for 3 hours. The mixture was evaporated to an oily residue. Theresidue was co-evaporated 2 times with toluene. Purification on a silicagel column (10 g) with CH₂Cl₂/MeOH solvent system (4-10% gradient;target compound eluted with 8% MeOH) afforded 31a (35 mg, 78% yield).³¹P-NMR (DMSO-d₆): δ −4.19. MS: m/z 580 (M−1), 646 (M+46−1), 550(M−30−1).

Example 32 Preparation of Compound (32a)

To a solution of 3-1 (71 mg; 0.26 mmol) in THF (4 mL) under Ar was addedtriethylammonium bis(POM)phosphate (144 mg; 1.2 equiv), and theresulting mixture was cooled in an ice-bath, and diisopropylethyl amine(0.18 mL; 4 equiv) was added. BOP-Cl (132 mg; 2 equiv) and3-nitro-1,2,4-triazole (59 mg; 2 equiv) was then added. The reactionmixture was stirred at 0° C. for 1 hour. The mixture was diluted withCH₂Cl₂ (50 mL) and washed with saturated aq. NaHCO₃ (2×10 mL) and brine.The combined aqueous layers were back extracted with CH₂Cl₂ (˜20 mL).The combined organic extract was dried (Na₂SO₄), evaporated, and theresidue was purified on silica (10 g column) with CH₂Cl₂/MeOH solventsystem (4-10% gradient). Compound 32a was repurified by RP-HPLC (35-90%B; A: water, B: MeOH). Yield 75 mg (50%). ³¹P-NMR (DMSO-d₆): δ −4.14.MS: m/z 627 (M+46−1), 551 (M−30−1).

Example 33 Preparation of Compound (33a)

Preparation of (4-2):

To a solution of 4-1 (0.29 g; 0.5 mmol) in MeCN (8 mL) was added5-ethylthio-1H-tetrazole in MeCN (0.25 M; 2.4 mL; 1.2 equiv).BisSATE-phosphoramidate (0.24 g; 1.05 equiv.) in MeCN (1.5 mL) was addedover 90 mins. The reaction mixture was stirred for 4 hours at R.T., andthen cooled to −40° C. MCPBA (0.23 g; 2 equiv.) in CH₂Cl₂ (3 mL) wasadded. The mixture was allowed to warm to R.T. and diluted with EtOAc(50 mL). The mixture was washed with 10% aq. NaHSO₃ (2×10 mL), saturatedaq. NaHCO₃ (2×10 mL) and brine. The mixture was then dried (Na₂SO₄). Theevaporated residue was purified on silica (10 g column) with CH₂Cl₂/MeOHsolvent system (4-10% gradient) to afford 4-2 (0.26 g, 55% yield).

Preparation of (33a):

A solution of 4-2 (0.21 g; 0.22 mmol) in 80% aq. AcOH (15 mL) wasstirred 4 hours at R.T. The mixture was evaporated and purified onsilica (10 g column) with CH₂Cl₂/MeOH solvent system (4-10% gradient).Yield: 0.13 g (90%). ³¹P-NMR (DMSO-d₆): δ −2.00. MS: m/z 686 (M+46−1).

Example 34 Preparation of Compounds (34a)-(34e)

1,2,4-Triazol (42 mg, 0.6 mmol) was suspended of dry CH₃CN (1 mL).Triethylamine was added (0.088 mL, 0.63 mmol), and the mixture wasvortexed to obtain a clear solution. After addition of POCl₃ (0.01 mL,0.1 mmol), the mixture was vortexed and left for 20 min. The mixture wasthen centrifugated. The supernatant was added to the protectednucleoside (0.05 mmol), and the mixture was kept at ambient temperaturefor 1 hour. Tris(tetrabutylammonium) hydrogen pyrophosphate (180 mg, 0.2mmol) was added, and the mixture was kept for 2 hours at R.T. Thereaction was quenched with water, evaporated, dissolved in 80% formicacid and left for 2 hours at R.T. Formic acid was evaporated, and theresidue dissolved in water (5 mL) and extracted with EA (2×2 mL). Theaqueous fraction was loaded onto column HiLoad 16/10 with Q SepharoseHigh Performance (linear gradient of NaCl from 0 to IN in 50 mMTRIS-buffer (pH=7.5)). Fractions containing the triphosphate werecombined, concentrated and desalted by RP HPLC on Synergy 4 micronHydro-RP column (Phenominex) using a linear gradient of methanol from 0to 20% in 50 mM triethylammonium acetate buffer (pH 7.5) for elution.The following compounds shown in Table 1 were synthesized according thisprocedure:

TABLE 1 Triphosphates obtained from Example 34 Compound ³¹P NMR Pα ³¹PNMR Pβ ³¹P NMR Pγ MS (M⁻)

−11.31 d −20.82 t −5.48 d 550.2

−9.13  d −18.18 t −2.85 d 548.2

−10.95 d −20.62 bs −5.37 bs 552.2

−11.24 d −20.82 t −5.48 d 554.2

−12.06 d −20.97 t −5.69 d 549.2

Example 35 Preparation of Compound (35a)

1,2,4-Triazol (42 mg, 0.6 mmol) was suspended in dry CH₃CN (1 mL).Triethylamine was added (0.088 mL, 0.63 mmol), and the mixture wasvortexed to obtain a clear solution. After addition of POCl₃ (0.01 mL,0.1 mmol), the mixture was vortexed and left for 20 mins. The mixturewas centrifugated, and the supernatant was added to the protectednucleoside (0.05 mmol). The mixture was kept at ambient temperature for1 hour. Tris(tetrabutylammonium) hydrogen pyrophosphate (180 mg, 0.2mmol) was added, and the mixture was kept for 2 hours at R.T. Thereaction was quenched with water, evaporated, dissolved in ammoniumhydroxide and left for 2 hours at R.T. The solvent was evaporated, andthe residue dissolved in water (10 mL). The mixture was loaded onto acolumn HiLoad 16/10 with Q Sepharose High Performance. Separation wasdone in linear gradient of NaCl from 0 to 1N in 50 mM TRIS-buffer(pH7.5). The fractions containing the product were combined,concentrated and desalted by RP HPLC on Synergy 4 micron Hydro-RP column(Phenominex). A linear gradient of methanol from 0 to 20% in 50 mMtriethylammonium acetate buffer (pH 7.5) was used for elution. MS (M−1):532.1. ³¹P-NMR (δ ppm): −5.12 (d), −11.31 (d) and −20.43 (t).

Example 36 Preparation of Compounds (36a)-(36d)

2′-Deoxy-2′-fluoro-4′-alkyl-cytidine (0.09 mmol) was dissolved in themixture of DMF (5 mL) and N,N′-dimethylacetate in DMF (0.110 mL, 0.9mmol). The reaction mixture left at R.T. overnight. The solvent wasevaporated, and the residue purified by flash chromatography in gradientof methanol in DCM from 3% to 20%. The N-Protected nucleoside wasconcentrated in vacuum, dried and dissolved in dry trimethylphosphate(0.7 mL). The solution was cooled to 4° C. and POCl₃ (0.017 mL, 0.18mmol) was added. In 1 hour, tributylamine (0.102 mL, 0.3 mmol) was addedat R.T. Tributylammonium pyrophosphate (156 mg, 0.34 mmol) was thenadded. Dry DMF (about 0.100 mL) was added to solubilize pyrophosphate.After 2 hours, the reaction was quenched with TEAB-buffer. The productwas isolated by ion-exchange chromatography on AKTA Explorer asdescribed in Example 35. The fractions containing the product wereconcentrated and treated with NH₄OH for 2 hours at R.T. The product wasdesalted by RP HPLC as described in Example 35.

TABLE 2 Triphosphates obtained from Example 36 ³¹P NMR Pα ³¹P NMR Pβ ³¹PNMR Pγ MS (M⁻)

−11.38 bs −22.88 bs −7.62  bs 512.1

−11.49 bs −20.41 bs −5.34  bs 510.0

−11.96 bs −22.07 t −5.66  d 508.3

−11.90 d −23.23 t −10.66 d 514.0

−11.77 d −23.05 t −9.70  s 529.9

−11.74 d −23.37 t −10.85 d 539.2

−11.87 d −23.32 t −10.83 d 523.9

−11.48 d −23.26 t −10.63 d 526.1

−11.67 d −23.22 t −10.77 d 554.1

−11.97 d −23.34 t −10.92 d 523.9

Example 37 Preparation of Compounds (37a)

Compound 37a was synthesized by reaction of phosphor(tris-triazolide)with 4′-ethyl-2′-deoxy-2′-fluoro-uridine as described Examples 34 and35. MS (M−1): 513.1. ³¹P-NMR (δ ppm): −9.43 (bs), −11.68 (d) and −23.09(bs).

Example 38 Preparation of Compounds (38a)

The starting nucleoside (15 mg, 0.05 mmol) was dissolved in drytrimethylphosphate (3 mL). The solution was cooled to 4° C. POCl₃ (0.013mL, 0.125 mmol) was added, followed by pyridine (0.01 mL, 0.125 mmol).In 1 hour, tributylamine (0.035 mL, 0.125 mmol) was added at R.T.followed by tributylammonium pyrophosphate (156 mg, 0.34 mmol). Dry DMF(about 0.100 mL) was added to solubilize pyrophosphate. In 2 hours, thereaction was quenched with TEAB-buffer. The product was isolated byion-exchange chromatography on AKTA Explorer as described in Example 35.The fractions containing the product were concentrated and treated withNH₄OH for 2 hours at R.T. The product was desalted by RP HPLC asdescribed in Example 35. MS (M−1): 529.9. ³¹P-NMR (δ ppm): −9.42 (d),−11.59 (d) and −23.03 (t).

Example 39 Preparation of Compound (40a)

Preparation of (40-2):

To a solution of 40-1 (50.0 g, 205 mmol) in pyridine (250 mL) was addedDMTrCl (75.0 g, 225.0 mmol). The solution was stirred at R.T. for 15hours. MeOH (120 mL) was added, and the mixture was concentrated todryness under reduced pressure. The residue was dissolved in EA andwashed with water. The organic layer was dried over Na₂SO₄ andconcentrated to give the crude 5′-O-DMTr intermediate (80.52 g) as alight yellow solid. The intermediate was dissolved in anhydrous DMF (300mL), and K₂CO₃ (80.52 g, 583.2 mmol) was added followed by PMBCl (31.7g, 109.2 mmol). The mixture was stirred at R.T. overnight. The reactionwas diluted with EA and washed with brine. The organic phase was driedover Na₂SO₄ and concentrated to give crude 5′-O-DMTr-N-3-PMB FdU (98.8g) as a light yellow solid. The solid was dissolved in DMF (300 mL), andNaH (10.42 g, 260.5 mmol) was added followed by BnBr (73.8 g, 434.2mmol). The reaction was stirred at R.T. overnight and then was quenchedwith water. The solution was diluted with EA and washed with brine. Theorganic phase was dried over Na₂SO₄ and concentrated to give the crudefully blocked FdU intermediate, which was purified on a silica gelcolumn (PE:EA=10:1 to 3:1) to the pure fully blocked FdU (101.1 g). Theintermediate was treated with 80% HOAc (900 mL) at R.T. overnight, andthe solvent was removed. The residue was purified on a silica gel columnto give 40-2 as a white foam (42.1 g, 30.2% for 4 steps).

Preparation of (40-3):

To a solution of 40-2 (42.1 g, 92.6 mmol) in anhydrous CH₃CN (300 mL)was added IBX (28.5 g, 121.7 mmol) at R.T. The reaction mixture wasrefluxed for 1 hour and then cooled to 0° C. The precipitate wasfiltered-off, and the filtrate was concentrated to give the crudealdehyde (39.22 g) as a yellow solid. To a solution of the aldehyde(39.22 g) in 1,4-dioxane (250 mL) was added 37% CH₂O (28.1 mL, 345.6mmol) and 2N NaOH aqueous solution (86.4 mL, 172.8 mmol). The mixturewas stirred at R.T. for 2 hours and then neutralized with AcOH to pH=7.EtOH (200 mL) and NaBH₄ (19.7 g, 518.6 mmol) were added, stirred at R.T.for 30 mins. The mixture was quenched with saturated aqueous NH₄Cl, andextracted with EA. The organic layer was dried over Na₂SO₄ andconcentrated. The residue was purified by silica gel columnchromatography (PE:EA=4:1 to 2:1) to give 40-3 (25.5 g, 55.7%) as awhite solid.

Preparation of (40-4):

To a stirred solution of 40-3 (25.5 g, 52.5 mmol) in anhydrous pyridine(150 mL) and anhydrous CH₃CN (150 mL) was added BzCl (6.6 g, 52.47 mmol)dropwise at 0° C. The mixture was stirred at R.T. for 14 hours. Thereaction was quenched with H₂O, and the solution was concentrated. Theresidue was dissolved in EA and washed with saturated NaHCO₃. Theorganic layer was dried over Na₂SO₄ and concentrated. The residue waspurified on a silica gel column (PE/EA=5:4) to give the mono-Bzprotected intermediate (18.1 g, 60.0%) as a white foam. To a stirredsolution of this intermediate (18.1 g, 30.68 mmol) in DMF (100 mL) wereadded Cs₂CO₃ (30.0 g, 92.03 mmol) and BnBr (10.4 g, 61.36 mmol). Themixture was stirred at R.T. overnight. The reaction was quenched withsaturated NH₄Cl aq., extracted with EA and washed with brine. Thesolvent was removed to give crude 40-4 (19.3 g, 95.1%) as a light yellowsolid.

Preparation of (40-5):

To a stirred solution of 40-4 (19.3 g, 28.4 mmol) in anhydrous MeOH (230mL) was added NaOMe (24.9 g, 460 mmol) at R.T. The mixture was stirredfor 1 hour. The reaction was quenched with AcOH (10 mL) andconcentrated. The residue was purified on a silica gel column(PE/EA=1/2) to afford 40-5 (11.2 g, 54.0%) as a white solid.

Preparation of (40-6):

To a stirred solution of compound 40-5 (200 mg, 0.347 mmol) in anhydrousDCM (5 mL) was added DMP (168 mg, 0.674 mmol) at R.T. The mixture wasstirred at R.T. for 2 hours. The solvent was removed, and the residuewas purified on a silica gel column (PE:EA=5:1 to 1:1) to give thealdehyde crude as a light yellow solid (200 mg). To a stirred solutionof the aldehyde (200 mg) in anhydrous THF (5 mL) was added MeMgBr (1.0mL, 1.01 mmol) at −78° C. The mixture was stirred at −78° C. for 1 hour.The reaction was quenched with saturated NH₄Cl aq. and extracted withEA. The concentrated organic phase was purified by column chromatography(PE:EA=5:1 to 1:1) to give 40-6 (a mixture of stereomers, 135 mg, 65%)as a white solid.

Preparation of (40-7):

To a stirred solution of DAST (1.64 g, 10.17 mmol) in anhydrous toluene(40 mL) was added dropwise a solution of compound 40-6 (1.2 g, 2.03mmol) at −78° C. The mixture was stirred at −78° C. for 30 mins. Thesolution was warmed to 60° C. slowly and stiffing was continuedovernight. The mixture was poured into a saturated Na₂CO₃ solution. Theconcentrated organic phase was concentrated and purified on a silica gelcolumn (PE:EA=10:1 to 3:1) to afford 40-7 as a white solid (1.08 g,83.88%). ¹H NMR (CD₃OD, 400 MHz) δ 7.87 (d, J=8.4 Hz, 1H), 7.27-7.37 (m,12H), 6.82-6.84 (m, 2H), 6.14 (d, J=16.8, 2.0 Hz, 1H), 5.18-5.50 (m,4H), 4.96 (s, 2H), 4.45-4.88 (m, 7H), 3.67-3.89 (m, 5H).

Preparation of (40-8):

A mixture of compound 40-7 (0.91 g, 1.54 mmol) and CAN (2.53 g, 4.61mmol) in a 3:1 solution of MeCN:water (10 mL) was stirred at R.T.overnight. Brine (10 mL) was added, and the mixture was extracted withEA. The combined organic extracts were dried and evaporated underreduced pressure. Purification by chromatography on silica gel columnwith PE:EA=10:1 to 2:1 afforded 40-8 as a yellow solid (305 mg, 41.96%).

Preparation of (40-9):

To a stirred solution of 40-8 (350 mg, 0.74 mmol) in anhydrous MeCN (8mL) were added TPSCl (449 mg, 1.48 mmol), DMAP (180 mg, 1.48 mmol) andTEA (374 mg, 3.70 mmol) at R.T. The mixture was stirred at R.T.overnight. NH₄OH (15 mL) was added, and the mixture was stirred for 2hours. The solvent was removed, and the residue was purified on a silicagel column with PE:EA=8:1 to 1:1 to afford the crude (380 mg crude),which was dissolved in anhydrous DCM (10 mL). A mixture of MMTrCl (695mg, 2.25 mmol) and AgNO₃ (380 mg, 2.25 mmol) was added at R.T., and themixture was stirred at R.T. overnight. The solid was filtered off andwashed with DCM. The filtrate was washed with brine and dried overNa₂SO₄. The concentrated organic phase was purified on a silica gelcolumn (PE:EA=8:1 to 2:1) to afford 40-9 as a yellow solid (460 mg,81.33%).

Preparation of (40-10):

To a stirred solution of compound 40-9 (450 mg, 0.61 mmol) in acetonewere added ammonium formate (1.29 g, 20.6 mmol, in portions) and 10%palladium on carbon (1.0 g). The mixture was refluxed for 12 h. Thecatalyst was filtered off and washed with acetone. The filtrate wasdiluted with EA and washed with brine. The concentrated organic phasewas purified by column chromatography (DCM:MeOH=100:1 to 15:1) to afford40-10 as a white solid (250 mg, 72.8%). ¹H NMR (DMSO-d6, 400 MHz) δ 8.56(s, 1H), 7.73 (d, J=7.6 Hz, 1H), 7.14-7.28 (m, 12H), 6.84 (d, J=8.8 Hz,2H), 6.30 (d, J=7.6 Hz, 1H), 6.03-6.08 (m, 1H), 5.84 (d, J=5.2 Hz, 1H),5.33-5.35 (m, 1H), 4.97-5.18 (m, 1H), 4.86-4.90 (m, 1H), 4.34 (d, J=4.4Hz, 1H), 3.72 (s, 3H), 3.54-3.57 (m, 2H), 1.28 (dd, =6.4 Hz, J₂=25.6 Hz,3H). ESI-MS: m/z 563.50 [M+H]⁺.

Preparation of (40a):

40-10 (101 mg, 0.179 mmol) was dissolved in 80% HOAc (20 mL) at R.T. Themixture was stirred at 50° C. for 5 hours. The solvent was removed, andthe residue was co-evaporated with toluene twice. The residue waspurified by column chromatography (DCM:MeOH=100:1 to 10:1) to afford 40aas a white solid (36.6 mg, 70.26%). ¹H NMR (CD₃OD, 400 MHz) δ 7.98 (d,J=7.6 Hz, 1H), 6.20-6.24 (m, 1H), 5.92 (d, J=7.2 Hz, 1H), 5.17-5.30 (m,1H), 4.99-5.14 (m, 1H), 4.51-4.86 (m, 1H), 3.78 (d, J=1.6 Hz, 2H),1.35-1.43 (m, 3H). ESI-MS: m/z 291.84 [M+H]⁺, 582.81 [2M+H]⁺.

Example 40 Preparation of Compound (41a)

Preparation of (41-2):

To a solution of 41-1 (3 g, 4.8 mmol) in anhydrous DCM (50 mL) wereadded BzCl (1.3 g, 9.6 mmol), DMAP (1.1 g, 9.6 mmol) and NEt₃ (4 mL) atR.T. The reaction was stirred at R.T. for 2 hours. Water was added, andthe reaction was stirred for another 1 hour. The mixture was dilutedwith DCM (150 mL) and washed with water, 0.1M HCl and saturated aqueousNaHCO₃. The solvent was removed, and the crude product was purified bysilica gel column chromatography (25% EtOAc in PE) to give 41-2 as ayellow solid (2.8 g, 80.0%).

Preparation of (41-3):

A mixture of 41-2 (2.6 g, 3.6 mmol) and Pd(OAc)₂ (100 mg) in DCM (50 mL)was suspended in a solution of CH₂N₂ in Et₂O (generated by standardprocedure, 350 mL) at −78° C. The reaction was stirred to R.T.overnight. The mixture was quenched with HOAc, and the reaction wasstirred for another 1 hour. The mixture was diluted with EtOAc (150 mL)and washed with water and saturated aqueous NaHCO₃. The solvent wasremoved, and the crude was dissolved in NH₃.MeOH (sat., 100 mL). Thereaction was stirred to R.T. overnight. The crude product was purifiedby silica gel column chromatography (25% EtOAc in PE) to give 41-3 as ayellow solid (800 mg, 35.2%).

Preparation of (41-4):

To a solution of 41-3 (800 mg, 1.3 mmol) in anhydrous CH₃CN (50 mL) wereadded TPSCl (755 mg, 2.5 mmol), DMAP (305 mg, 2.5 mmol) and NEt₃ (400mg, 4 mmol) at R.T. The reaction was stirred at R.T. for 2 hours. NH₄OH(25 mL) was added, and the reaction was stirred for another 1 hour. Themixture was diluted with DCM (150 mL) and washed with water, 0.1M HCland saturated aqueous NaHCO₃. The solvent was removed, and the crudeproduct was purified by silica gel column chromatography (25% EtOAc inPE) to give 41-4 as a yellow solid (340 mg, 42.5%).

Preparation of (41a):

To a solution of 41-4 (200.0 mg) in MeOH (10 mL) was added NH₄F (600mg). The reaction was refluxed for 24 hours. The solvent was removed,and the residue was purified by column chromatography on silica gel(DCM: MeOH=15:1) to give 41a (50.0 mg, 55.9%) as a white solid. ¹H NMR(CD₃OD, 400 MHz) δ 8.13 (d, J=7.6 Hz, 1H), 6.01 (dd, J₁=2.4 Hz, J₂=15.6Hz, 1H), 5.85 (d, J=7.6 Hz, 1H), 5.04-4.89 (m, 1H), 4.52 (dd, J₁=5.2 Hz,J₂=19.6 Hz, 1H), 3.66 (s, 2H), 1.00-0.94 (m, 1H), 0.54-0.30 (m, 4H);ESI-MS: m/z 285.82 [M+H]⁺, 570.84 [2M+H]⁺.

Example 41 Preparation of Compound (42a)

Preparation of (42-2):

To a solution of 42-1 (50 g, 203 mmol) in anhydrous pyridine (200 mL)was added TBDPSCl (83.7 g, 304 mmol, 1.5 eq). The reaction was stirredovernight at R.T. The solution was concentrated under reduced pressureto give a syrup, which was partitioned between ethyl acetate and water.The organic layer was separated, washed with brine, dried over magnesiumsulfate and concentrated to give the 5′-OTBDPS ether as a white foam (94g). The crude ether was dissolved in anhydrous DCM (300 mL), and silvernitrate (66.03 g, 388.4 mmol, 2.0 eq) and collidine (235 mL, 1.94 mol,10 eq) were added. The mixture was stirred at R.T., and MMTrCl (239.3 g,776.8 mmol, 4 eq) was added. After being stirred overnight at R.T., themixture was filtered through Celite and filtrate was diluted with MTBE.The solution was washed successively with 1M citric acid, diluted brineand 5% sodium bicarbonate. The organic solution was dried over sodiumsulfate and concentrated under vacuum to give the fully protectedintermediate as a yellow foam. The crude intermediate was dissolved inanhydrous THF (250 mL) and treated with TBAF (60 g, 233 mmol, 1.2 eq).The mixture was stirred for 2 hours at R.T., and the solvent was removedunder reduced pressure. The residue was taken into ethyl acetate andwashed brine. After drying over magnesium sulfate, the solvent wasremoved in vacuo. The residue was purified by column chromatography(PE:EA=5:1 to 1:1) to give 42-2 as a white foam (91 g, 86.4%).

Preparation of (42-3):

To a solution of 42-2 (13.5 g, 26 mmol) in DCM (100 mL) was addedpyridine (6.17 mL, 78 mmol, 3 eq). The solution was cooled to 0° C. andDess-Martin periodinane (33.8 g, 78 mmol, 3 eq) was added. The mixturewas stirred for 4 hours at R.T. and quenched by the addition of a 4%Na₂S₂O₃/4% sodium bicarbonate aqueous solution (to pH 6, ˜150 mL). Themixture was stirred for another 15 mins. The organic layer wasseparated, washed with diluted brine and concentrated under reducedpressure. The residue was dissolved in dioxane (100 mL), and thesolution was treated with 37% aqueous formaldehyde (21.2 g, 10 eq) and2N aqueous sodium hydroxide (10 eq). The reaction mixture was stirred atR.T. overnight. The reaction was quenched with saturated NH₄Cl (˜150mL), and the mixture was concentrated under reduced pressure. Theresidue was partitioned between ethyl acetate and 5% sodium bicarbonate.The organic phase was separated, washed with brine, dried over magnesiumsulfate and concentrated. The residue was purified by columnchromatography (MeOH:DCM=100:1˜50:1) to give 42-3 as a white foam (9.2g, 83.6%).

Preparation of (42-4):

42-3 (23 g, 42.0 mmol) was co-evaporated with toluene twice. The residuewas dissolved in anhydrous DCM (250 mL) and pyridine (20 mL). Thesolution was cooled to −35° C. Triflic anhydride (24.9 g, 88.1 mmol, 2.1eq) was added dropwise over 10 mins. At this temperature, the reactionwas stirred for 40 mins and then was quenched with water (50 mL) at 0°C. The mixture was stirred 30 mins, and extracted with EA (150 mL×2).The organic phase was dried over Na₂SO₄, and filtered through a silicagel pad. The filtrate was concentrated under reduced pressure. Theresidue was purified by column chromatography (PE:EA=100:1-1:1) to give42-4 as a brown foam (30.0 g, 88.3%).

Preparation of (42-5):

42-4 (30 g, 36.9 mmol) was co-evaporated twice with toluene anddissolved in anhydrous DMF (150 mL). The solution was cooled to 0° C.,and treated with sodium hydride (60% in mineral oil; 1.5 g, 40.6 mmol).The reaction was stirred at R.T. for 1 h. Lithium chloride (4.6 g, 110.7mmol, 3 eq) was added. Stirring was continued for 2 hours when LCMSindicated complete conversion of the anhydro triflate intermediate toanhydro-chloro compound. The mixture was taken into 100 mL of halfsaturated ammonium chloride and ethyl acetate. The organic phase wasseparated, washed with diluted brine and concentrated under reducedpressure. The residue was dissolved in THF (150 mL), and the solutionwas treated with 1N aqueous sodium hydroxide (˜41 mL, 40.1 mmol, 1.1eq). The mixture was stirred at R.T. for 1 h. The reaction was dilutedwith half saturated sodium bicarbonate (˜60 mL) and extracted with EA.The organic phase was dried (magnesium sulfate) and concentrated underreduced pressure. The residue was purified by column chromatography(DCM:MeOH=300:1˜60:1) to give 42-5 as a yellow foam (18.3 g, 87.6%).

Preparation of (42-6):

To a solution of 42-5 (18.3 g, 32.33 mmol) in anhydrous DCM (150 mL) wasadded TBSCl (17.7 g, 64.6 mmol) and imidazole (6.6 g, 97 mmol). Thereaction was stirred overnight at R.T. The reaction was diluted withwater and extracted with DCM. The organic layer was separated, washedwith brine, dried over Na₂SO₄ and concentrated. The residue was purifiedby column chromatography (DCM:MeOH=300:1˜80:1) to give 42-6 as a whitefoam (18.4 g, 83.7%).

Preparation of (42-7):

A solution of 42-6 (18.4 g, 27.1 mmol), DMAP (6.6 g, 54.0 mmol) and TEA(5.4 g, 54.0 mmol) in MeCN (450 mL) was treated with2,4,6-triispropylbenzenesulfonyl chloride (16.3 g, 54.0 mmol). Themixture was stirred at R.T. for 3 hours. NH₄OH (70 mL) was added, andthe mixture was stirred for 2 hours. The solution was evaporated underreduced pressure, and the residue was purified on a silica gel column(DCM/MeOH=100:1 to 15:1) to give the crude (18.0 g). The crude wasdissolved in anhydrous DCM (150 mL). Collidine (8.1 g, 66.3 mmol, 2.5eq), silver nitrate (4.5 g, 26.5 mmol, 1.0 eq) and DMTrCl (13.4 g, 39.7mmol, 1.5 eq) were added. The reaction was stirred overnight at R.T. Themixture was filtered through Celite. The filtrate was washed with brineand extracted with DCM. The organic layer was separated, dried overNa₂SO₄ and concentrated. The residue was purified by columnchromatography (PE:EA=60:1˜3:1) as a yellow foam. The foam was dissolvedin THF (150 mL) and TBAF (10.4 g, 39.7 mmol, 1.5 eq) was added. Thereaction was stirred at R.T. After being concentrated, the mixture waswashed with brine and extracted with EA. The organic layer wasseparated, dried over Na₂SO₄ and concentrated. The residue was purifiedby column chromatography (PE:EA=60:1˜EA) to give 42-7 as a yellow foam(21.3 g, 92.4%).

Preparation of (42-8):

To a solution of 42-7 (2.0 g, 2.3 mmol) in anhydrous DCM (20 mL) wasadded Dess-Martin periodinane (1.95 g, 4.6 mmol) at 0° C. undernitrogen. The reaction was stirred at R.T. for 5 hours. The mixture wasdiluted with EtOAc (100 mL), and washed with a mixture of saturatedaqueous Na₂S₂O₃ and saturated aqueous NaHCO₃. The crude product waspurified by column chromatography on silica gel (PE:EtOAc=2:1) to give42-8 (1.8 g, 90%) as a yellow solid.

Preparation of (42-9):

To a solution of tetramethyl methylenediphosphonate (390 mg, 1.68 mmol)in anhydrous THF (10 mL) was added NaH (84 mg, 2.1 mmol) at 0° C. undernitrogen. The reaction was stirred at 0° C. for 30 min. A solution of42-8 (1.2 g, 1.4 mmol) in anhydrous THF (10 mL) was added dropwise at 0°C. The mixture was stirred at R.T. for 1 h. The reaction was quenchedwith saturated aqueous NH₄Cl, and the crude product was purified bycolumn chromatography on silica gel (DCM: MeOH=150:1) to give 42-9 (1.2g, 88.2%) as a yellow solid. ¹H NMR (DMSO-d6, 400 M Hz) δ 8.51 (s, 1H),7.46-7.09 (m, 22H), 6.88-6.82 (m, 6H), 6.62 (q, J₁=17.2 Hz, J₂=22.4 Hz,1H), 6.12 (d, J=7.2 Hz, 1H), 5.86-5.75 (m, 2H), 5.43 (d, J=25.2 Hz, 1H),4.63 (dd, J₁=4.8 Hz, J₂=21.2 Hz, 1H), 4.45 (d, J=12.0 Hz, 1H), 3.94 (d,J=12.0 Hz, 1H), 3.72 (s, 9H), 3.53 (q, J₁=11.2 Hz, J₂=16.0 Hz, 6H);ESI-MS: m/z 971.59 [M+H]⁺.

Preparation of (42a):

A solution of 42-9 (300 mg) in 80% HOAc (26 mL) was stirred at 80-90° C.for 2 h. The solvent was removed, and the crude product was purified bycolumn chromatography on silica gel (DCM:MeOH 20:1) to give 42a (70 mg,57%) as a white solid. ¹H NMR (DMSO-d6, 400 MHz) δ 7.61 (d, J=7.6 Hz,1H), 7.35 (d, J=15.2 Hz, 2H), 6.72 (q, J₁=17.6 Hz, J₂=24.4 Hz, 1H), 6.23(d, J=6.0 Hz, 1H), 5.99-5.85 (m, 2H), 5.74 (q, J=7.2 Hz, 1H), 5.37-5.21(m, 1H), 4.69-4.61 (m, 1H), 3.96 (d, J=12.4 Hz, 1H), 3.82 (d, J=12.0 Hz,1H), 6.72 (q, J₁=5.2 Hz, J₂=10.8 Hz, 6H); ESI-MS: m/z 397.81 [M+H]⁺.

Example 42 Preparation of Compound (43a)

Preparation of (43-2):

To a stirred solution of 43-1 (3.8 g, 6.6 mmol) in anhydrous DMF (100mL) was added NaH (2.2 g) followed by CH₃I (9.3 g, 66 mmol) at 0° C.Stirring was continued at R.T. overnight. The reaction was quenched withsaturated NH₄Cl aq. The mixture was diluted with EA and washed withbrine. The organic layer was dried over Na₂SO₄ and concentrated. Theresidue was purified by silica gel column chromatography (PE:EA=2:1) togive 43-2 (3.0 g, 70%) as a white solid.

Preparation of (43-3):

A mixture of 43-2 (3.0 g, 5.1 mmol) and CAN (5.56 g, 10.2 mmol) in a 3:1solution of MeCN:Water (16 mL) was stirred at R.T. overnight. Thesolution was diluted with brine (10 mL) and was extracted with EA. Thecombined organic extracts were dried and evaporated under reducedpressure. Purification by chromatography on silica (PE:EA=1:1) gave 43-3as a yellow solid (1.71 g, 72%).

Preparation of (43-4):

To a stirred solution of 43-3 (1.7 g, 3.6 mmol) in anhydrous MeCN (50mL) were added TPSCl (2.2 g, 7.2 mmol), DMAP (880 mg, 7.2 mmol) and TEA(1.1 g, 10.8 mmol) at R.T. The mixture was stirred at R.T. overnight.NH₄OH (25 mL) was added, and the mixture was stirred for 2 hours. Thesolvent was removed, and the residue was purified on a silica gel column(PE:EA=8:1 to 2:1) to give the intermediate (1.4 g). The intermediatewas dissolved in anhydrous DCM (30 mL), and MMTrCl (1.6 g, 5.2 mmol),AgNO₃ (1.4 g, 7.8 mmol) and collidine (1.57 g, 13 mmol) were added. Themixture was stirred at R.T. overnight. The solid was filtered off andwashed with DCM. The filtrate was washed with brine and dried overNa₂SO₄. The concentrated organic phase was purified on a silica gelcolumn (PE:EA=3:2) to give 43-4 (1.1 g, 57.9%) as a white solid.

Preparation of (43-5):

To a stirred solution of 43-4 (550 mg, 0.74 mmol) in acetone were addedammonium formate (1.0 g, 15.8 mmol, in portions) and 10% palladium oncarbon (1.0 g). The mixture was refluxed for 48 hours. The catalyst wasfiltered off and washed with the acetone. The filtrate was diluted withEA, washed with brine and dried. The concentrated organic phase waspurified by column chromatography (DCM:MeOH=50:1) to give 43-5 (330 mg,72%).

Preparation of (43a):

43-5 (200 mg, 0.36 mmol) was dissolved in 80% CH₃COOH (20 mL) at R.T.The mixture was stirred at 60° C. for 12 hours. The solvent was removed.The residue was purified by column chromatography (DCM:MeOH=10:1), andthe resulting solid was washed with DCM to give pure 43a as a whitesolid (44 mg, 42%). ¹H NMR (CD₃OD, 400 MHz) δ 8.02 (d, J=7.2 Hz, 1H),6.14 (dd, J=3.6 Hz, J₂=15.2 Hz, 1H), 5.88 (d, J=7.2 Hz, 1H), 5.10 (ddd,J=4.0 Hz, J₂=5.2 Hz, J₃=53.6 Hz, 1H), 4.47 (dd, J₁=5.2 Hz, J₂=14.8 Hz,1H), 3.84 (d, J=12.0 Hz, 1H), 3.70 (d, J=12.0 Hz, 1H), 3.58-3.64 (m,2H), 3.36 (s, 3H). ESI-MS: m/z 290 [M+H]⁺.

Example 43 Preparation of Compound (44a)

To a solution of triethylammonium bis(POM)phosphate (0.3 mmol, preparedfrom 100 mg of bis(POM)phosphate and 50 μL of Et₃N) in THF (3 mL) wasadded nucleoside 44-1 (150 mg; 0.26 mmol). The mixture was cooled inice-bath. Diisopropylethyl amine (0.18 mL; 4 equiv) was added then,followed by BOP-Cl (132 mg; 2 equiv) and 3-nitro-1,2,4-triazole (59 mg;2 equiv). The reaction mixture was stirred at 0° C. for 90 mins., andthen diluted with CH₂Cl₂ (30 mL) and washed with saturated aq. NaHCO₃and brine. The combined aqueous layers were back extracted with CH₂Cl₂.The combined organic extract was dried (Na₂SO₄), evaporated, and theresidue purified on silica (10 g column) with CH₂Cl₂/i-PrOH solventsystem (3-10% gradient). The obtained mixture of products were treatedfor 30 mins at 35° C. with 80% aq. HCOOH, and then evaporated andcoevaporated with toluene. The evaporated residue was purified on silica(10 g column) with CH₂Cl₂/MeOH solvent system (5-10% gradient) to obtain44a (8 mg, 5%). ³¹P-NMR (DMSO-d₆): δ −5.07. MS: m/z=668 (M+46−1).

Example 44 Preparation of Compound (45a)

Preparation of (45-2):

To a solution of triethylammonium bis(POM)phosphate (0.7 mmol, preparedfrom 233 mg of bis(POM)phosphate and 0.1 mL of Et₃N) in THF (8 mL) wasadded nucleoside 45-1 (253 mg; 0.42 mmol), followed by diisopropylethylamine (0.36 mL; 5 equiv), BOP-Cl (268 mg; 2.5 equiv) and3-nitro-1,2,4-triazole (120 mg; 2.5 equiv). The reaction mixture wasstirred at R.T. for 2 hours. The mixture was diluted with CH₂Cl₂ (40 mL)and washed with saturated aq. NaHCO₃ and brine. The combined aqueouslayers were back extracted with CH₂Cl₂. The combined organic extract wasdried (Na₂SO₄), evaporated, and the residue was purified on silica (10 gcolumn) with hexanes/EtOAc solvent system (40-100% gradient) to yield45a (180 mg, 47%).

Preparation of (45a):

A solution of compound 45-2 (0.12 g; 0.13 mmol) in 80% aq. HCOOH (8 mL)was stirred 30 mins. at R.T. The mixture was evaporated, coevaporatedwith toluene and purified on silica (10 g column) with CH₂Cl₂/MeOHsolvent system (4-10% gradient) to yield 45a (55 mg, 70%). ³¹P-NMR(DMSO-d₆): δ −4.36. MS: m/z=647 (M+46−1).

Example 45 Preparation of Compound (46a)

Preparation of (46-2):

A mixture of 46-1 (170 mg; 0.3 mmol) in pyridine (3 mL) and isobutyricanhydride (0.1 mL; 2 equiv) was stirred o/n at R.T. The mixture wasconcentrated, and the residue was partitioned between EtOAc (30 mL) andsaturated aq. NaHCO₃. The organic layer was washed with water, brine anddried (Na₂SO₄). The residue was purified on silica (10 g column) with ahexanes/EtOAc solvent system (30 to 100% gradient) to afford 46-2 (180mg, 85%).

Preparation of (46a):

A solution of 46-2 (0.18 g; 0.25 mmol) in 80% aq. HCOOH (5 mL) washeated for 3 hours at 36° C. The mixture was then evaporated,coevaporated with toluene and purified on silica (10 g column) with aCH₂Cl₂/MeOH solvent system (4-10% gradient) to afford 46a (75 mg, 70%).MS: m/z=434 (M+1).

Example 46 Preparation of Compound (47a)

Preparation of (47-2):

47-2 was prepared from 46-1 (274 mg, 0.46 mmol) and propyonic anhydride(0.12 mL, 2 equiv.) in pyridine (5 mL) in the same manner as describedfor 46-2 (260 mg, 80%).

Preparation of (47a):

47-2 (120 mg, 0.2 mmol) was treated with 80% aq. HCOOH at R.T. for 3hours. The mixture was evaporated, coevaporated with toluene andpurified on silica (10 g column) with a CH₂Cl₂/MeOH solvent system(4-10% gradient) to yield 47a (62 mg, 75%). MS: m/z=404 (M−1).

Example 47 Preparation of Compound (48a)

Preparation of (48-2):

48-2 was prepared from 46-1 (150 mg, 0.27 mmol) and valeric anhydride(0.11 mL, 2 equiv.) in pyridine (3 mL) in the same manner as describedfor 46-2 (150 mg, 73%).

Preparation of (48a):

48-2 (140 mg, 0.18 mmol) was treated with 80% aq. HCOOH at R.T. for 3hours. The mixture was evaporated and purified on silica (10 g column)with a CH₂Cl₂/MeOH solvent system (4-10% gradient) to yield 48a (70 mg,84%). MS: m/z=462 (M+1).

Example 48 Preparation of Compounds (49a), (50a) and (51a)

Preparation of (49-2), (50-2) and (51-2):

To a solution of 46-1 (1.26 g, 2.12 mmol) in pyridine (15 mL) were addedn-octanoic acid (0.34 mL, 1.0 equiv.), DCC (60% in xylene; 0.81 mL, 1equiv.) and DMAP (52 mg; 0.2 equiv.). The resulting mixture was stirredfor 6 hours at R.T. The mixture was evaporated, and the residuepartitioned between CH₂Cl₂ (100 mL) and saturated aq. NaHCO₃ (25 mL).The organic layer was washed with water, brine and dried (Na₂SO₄). Theresidue was treated with toluene. The solid material was filtered off,and the filtrate was purified on silica (25 g column) with ahexanes/EtOAc solvent system (30-100% gradient) to yield 49-2 (0.57 g,32%), 50-2 (0.18 g, 12%), and 51-2 (0.2 g, 13%).

Preparation of (49a):

A mixture of 49-2 (114 mg, 0.13 mmol) and 80% aq. formic acid wasstirred for 3 hours at R.T. The mixture was evaporated and coevaporatedwith toluene and purified on silica (10 g column) with a CH₂Cl₂/MeOHsolvent system (2-8% gradient) to yield 49a (53 mg, 75%). MS: m/z=544(M−1).

Preparation of (50a):

50a (44 mg, 75% yield) was prepared from 50-2 (104 mg, 0.14 mmol) in thesame manner as described for 49a by using a 4-10% gradient of MeOH inCH₂Cl₂ for purification. MS: m/z=418 (M−1).

Preparation of (51a):

51a (60 mg, 71% yield) was prepared from 50-2 (140 mg, 0.2 mmol) in thesame manner as described for 49a by using a 4-10% gradient of MeOH inCH₂Cl₂ for purification. MS: m/z=418 (M−1).

Example 49 Preparation of Compound (52a)

Preparation of (52-2):

A solution of N-(tert-butoxycarbonyl)-L-valine (0.41 g, 1.9 mmol) andcarbonyldiimidazole (0.31 g, 1.9 mmol) in THF (9 mL) was stirred at R.T.for 1.5 hours. The mixture was then stirred at 40° C. for 20 mins. Themixture was added to a solution of 7a (0.42 g, 1.43 mmol) and DMAP (25mg, 0.2 mmol) in DMF (8 mL) and TEA (4 mL) at 80° C. The reactionmixture was stirred at 80° C. for 1 h, then cooled and concentrated. Theresidue was partitioned between tert-butyl methyl ether (100 mL) andwater. The organic layer was washed with water, brine and dried(Na₂SO₄). The residue was purified on silica (25 g column) with aCH₂Cl₂/MeOH solvent system (2-10% gradient) to yield 52-2 (0.32 g, 90%in the mixture with 5′-isomer), which was repurified by RP-HPLC (10-100%B; A: water, B: MeOH). Yield: 0.25 g (35%).

Preparation of (52a):

A solution of 52-2 (0.12 g; 0.24 mmol) in EtOAc (0.6 mL) was treatedwith HCl/dioxane (4 M; 0.6 mL) for 20 mins. with vigorous shaking. Thewhite precipitate was filtered, washed with diethyl ether and dried toyield 52a as the dihydrochloride salt (95 mg; 85%). MS: m/z=391 (M−1).

Example 50 Preparation of Compound (53a)

Preparation of (53-2):

To a solution of N-Boc-Val-OH (0.16 g, 0.74 mmol) and Et₃N (0.14 mL, 1.0mmol) in THF was added 53-1. The resulting mixture was evaporated,coevaporated with pyridine and toluene and dissolved in THF (4 mL).DIPEA (0.38 mL, 2.2 mmol) was added, followed by BOP-Cl (0.28 g, 1.1mmol) and 3-nitro-1,2,4-triazole (0.13 g, 1.1 mmol). The reactionmixture was stirred at R.T. for 1 h. The mixture was diluted with CH₂Cl₂(40 mL) and washed with saturated aq. NaHCO₃ and brine. The combinedaqueous layers were back extracted with CH₂Cl₂. The combined organicextract was dried (Na₂SO₄), evaporated, and the residue was purified onsilica (10 g column) with a hexanes/0.5% Et₃N/EtOAc solvent system(20-100% gradient) to yield 53-2 (0.39 g, 81%).

Preparation of (53a):

A mixture of 14-2 (0.37 g, 0.33 mmol) and 80% aq. HCOOH (10 mL) wasstirred at R.T. for 3 hours. The mixture was evaporated, and the residuewas partitioned between water and CH₂Cl₂. The aqueous layer was washedwith CH₂Cl₂ and evaporated. The solid residue was suspended in EtOAc(1.5 mL) and treated with 4N HCl in dioxane (1.5 mL) with vigorousshaking. The solid was filtered, washed with diethyl ether and purifiedby RP-HPLC (A: 0.5N HCOOH in water, B: 0.5N HCOOH in acetonitrile). Theresulting formic acid salt of 5′-O-valyn ester was converted into 53adihydrochloride salt (63 mg, 40%) by suspending in EtOAc (2 mL) andtreatment with 4N HCl/dioxane (2 mL). MS: m/z=391 (M−1).

Example 51 Preparation of Compound (39a)

Preparation of (39-2):

A solution of 39-1 (1.3 g, 1.4 mmol) in anhydrous MeOH (20 mL) wascharged with Pd/C (1.3 g) and stirred at 25° C. under hydrogen (1 atm)atmosphere for 1 hour. The solution was filtered, evaporated to dryness,and purified on a silica gel column (DCM:MeOH=100:1 to 50:1) to give39-2 (1.2 g, 92.3%) as a white solid.

Preparation of (39-3):

To a solution of 39-2 (1.2 g, 1.3 mmol) in MeOH (40 mL) was added NH₄F(370 mg, 10 mmol) at 25° C. and stirred at 60° C. for 6 hours. Thesolution was filtered, evaporated to dryness, and purified on a silicagel column (DCM:MeOH=200:1 to 20:1) to give 39-3 as a white solid (249mg, 30.7%). ¹H NMR (MeOD, 400 MHz) δ 7.92 (s, 1H), 7.19-7.33 (m, 12H),6.83-6.85 (m, 2H), 5.50 (dd, J₁=4.0 Hz, J₂=14.8 Hz, 1H), 4.19-4.88 (m,1H), 4.22 (dd, J₁=5.2 Hz, J₂=16.0 Hz, 1H), 3.76 (s, 3H), 3.41 (dd,J₁=12.0 Hz, J₂=36.8 Hz, 2H), 1.52-1.74 (m, 2H), 0.87 (t, J=7.6 Hz, 3H);ESI-LCMS: m/z 586.1 [M+H]⁺.

Preparation of (39a):

A solution of 39-3 of 80% formic acid/20% water (3 mL) stood at RT for 2hours, and then was concentrated to dryness. The residue wasco-evaporated with MeOH/toluene (3 times) and then ethyl acetate added.The suspension in ethyl acetate was heated at 70° C. for 5 mins. Thesolvent was removed using a pipet. This washing was repeated 3 times.The resulting product (44 mg) was further purified on reverse-phase HPLCusing acetonitrile/water as mobile phase to give 39a (20 mg) as anoff-white solid. ¹H NMR (DMSO, 400 MHz) δ 7.92 (s, 1H), 10.82 br, 1H),7.96 (s, 1H), 6.56 (s, 2H), 5.99 (dd, J=6.0, 12.8 Hz, 1H), 5.65 (d,J=4.8 Hz, 1H), 5.58, 5.45 (2t, J=5.2 Hz, 0.5H, 0.5H), 5.25 (br, 1H),4.19-4.88 (m, 1H), 4.22 (dd, J₁=5.2 Hz, J₂=16.0 Hz, 1H), 3.76 (s, 3H),3.41 (dd, J₁=12.0 Hz, J₂=36.8 Hz, 2H), 1.52-1.74 (m, 2H), 0.87 (t, J=7.6Hz, 3H); ESI-LCMS: m/z 443.6 [M+6-methyl-2-heptylamine)]⁺.

Example 52 Preparation of Compounds (55a) and (56a)

1,2,4-Triazol (21 mg, 0.3 mmol) was dissolved in the mixture of CH₃CN(0.7 mL) and Et₃N (44 μL, 0.31 mmol). POCl₃ (9 ul, 0.1 mmol) was added,and the mixture was kept at R.T. for 20 mins. The white precipitate wasfiltered, and the filtrate added to the dry nucleoside (28 mg, 0.05mmol). The reaction was controlled by TLC and monitored by thedisappearance of the starting nucleoside. After completion of thereaction, tetrabutylammonium salt of pyrophosphate (150 mg) was added,followed by DMF (0.5 mL) to get a homogeneous solution. After 1.5 hoursat ambient temperature, the reaction was diluted with water (4 mL) andextracted with DCM (2×5 mL). The combined organic extracts wereevaporated, dissolved in 5 mL of 80% HCOOH and left for 2 hours at R.T.The reaction mixture was concentrated and distributed between water (5mL) and DCM (5 mL). The aqueous fraction was loaded on the column HiLoad16/10 with Q Sepharose High Performance. Separation was done in a lineargradient of NaCl from 0 to 1N in 50 mM TRIS-buffer (pH7.5). Twofractions were obtained. The first fraction, containing themonophosphate (55a) was eluted at 70-75% B. and triphosphate (56a) waseluted at 75-80% B. Both fractions were desalted by RP HPLC on Synergy 4micron Hydro-RP column (Phenominex). A linear gradient of methanol from0 to 30% in 50 mM triethylammonium acetate buffer (pH 7.5) was used forelution. The corresponding fractions were combined, concentrated andlyophilized 3 times to remove excess of buffer.

Example 53 Preparation of Compounds (56b-e)

1,2,4-Triazol (21 mg, 0.3 mmol) was dissolved in the mixture of CH₃CN(0.7 mL) and Et₃N (44 μL, 0.31 mmol). POCl₃ (9 ul, 0.1 mmol) was added,and the mixture was kept at R.T. for 20 mins. The white precipitate wasfiltered, and the filtrate added to the dry nucleoside (28 mg, 0.05mmol). The reaction was controlled by TLC and monitored by thedisappearance of the starting nucleoside. After completion of thereaction, tetrabutylammonium salt of pyrophosphate (150 mg) was addedfollowed by DMF (0.5 mL) to get a homogeneous solution. After 1.5 hoursat ambient temperature, the reaction was diluted with water (4 mL) andextracted with DCM (2×5 mL). The combined organic extracts wereevaporated, dissolved in 5 mL of 80% HCOOH and left for 4 hours at 38°C. The reaction mixture was concentrated and distributed between water(5 mL) and DCM (5 mL). The aqueous fraction was loaded on the columnHiLoad 16/10 with Q Sepharose High Performance. Separation was done in alinear gradient of NaCl from 0 to 1N in 50 mM TRIS-buffer (pH7.5). Twofractions were obtained. The triphosphate (56b-e) was eluted at 75-80%B. Desaltin was performed by RP HPLC on Synergy 4 micron Hydro-RP column(Phenominex). A linear gradient of methanol from 0 to 30% in 50 mMtriethylammonium acetate buffer (pH 7.5) was used for elution. Thecorresponding fractions were combined, concentrated and lyophilized 3times to remove excess of buffer.

TABLE 3 Triphosphates obtained from Example 53 Structure MS (M − 1) P(α)P(β) P(γ)

373.00 +3.64  (s) NA NA

532.95 −6.67  −6.74  (d) −21.87 (t) −11.51 −11.63 (d)

526.05 −6.33  −6.74  (d) −22.48 (t) −11.53 −11.64 (d)

516.00 −63.2  (bs) −22.45 (t) −11.64 (d)

524.4  −10.57 −10.67 (d) −23.31 (t) −11.31 −11.94 (d)

529.8  −6.17  (bs) −21.96 (bs) −11.42 (bs)

Example 54 Preparation of Compound (57a)

2′-Deoxy-2′-fluoro-4′-C-(ethenyl)guanosine (25a, 31 mg, 0.1 mmol) wasdissolved in dry pyridine (3 mL). Isobutyric anhydrate (50 μL, 0.3 mmol)was added. The reaction mixture was kept at ambient temperature. After40 hours, isobutyric anhydrate (100 μL, 0.6 mmol) was added, and thereaction mixture was left overnight. The pyridine was evaporated. Theresidue was purified by silica gel chromatography using a gradient ofmethanol in DCM from 3% to 10% to yield 57a (20 mg, 50%). ¹H NMR(DMSO-d6) δ: 10.72 (s, 1H), 7.88 (s, 1H), 6.47 (s, 2H), 6.18-6.13 (dd,1H), 5.90-5.83 (dd, 1H), 5.79-5.62 (m, 2H), 5.49-5.44 (d, 1H), 5.35-5.32(d, 1H), 4.28-4.25 (d, 1H), 4.12-4.10 (d, 1H), 2.60-2.45 (m, 2H),1.12-1.09 (m, 6H), 1.02-0.96 (m, 6H); m/z 452 (M+1).

Example 55 Preparation of Compound (58a)

Preparation of (58-2):

To a solution of 58-1 (50.0 g, 205 mmol) in pyridine (250 mL) was addedDMTrCl (75.0 g, 225.0 mmol). The solution was stirred at R.T. for 15hours. MeOH (120 mL) was added, and the mixture was concentrated todryness under reduced pressure. The residue was dissolved in EA andwashed with water. The organic layer was dried over Na₂SO₄ andconcentrated to give the crude DMTr protected derivative (80.5 g, 89%)as a light yellow solid. Dried K₂CO₃ (80.52 g, 583.2 mmol) and thenPMBCl (31.7 g, 109.2 mmol) were added to a stirred solution of the DMTrprotected derivative (80 g, 146 mmol) in anhydrous DMF (300 mL). Thestirring was continued at ambient temperature for overnight. Thereaction was monitored by TLC. The mixture was diluted with EA andwashed with water. The organic layer was dried over Na₂SO₄ andconcentrated to give 58-2 (98.8 g, 90%) as light yellow solid.

Preparation of (58-3):

NaH (10.4 g, 260.5 mmol) and BnBr (73.8 g, 434.2 mmol) were added to astirred solution of 58-2 (98.8 g, 147.9 mmol) in anhydrous DMF (300 mL),and the stiffing was continued at 25° C. overnight. The reaction wasmonitored by TLC. The reaction was quenched with water, extracted withEA and washed with brine. The solvent was removed, and the residue waspurified on silica gel (PE:EA=10:1 to 3:1) to give the Bn protectedderivative (101.1 g, 90%) as a light yellow solid. The Bn protectedderivative (101.1 g, 133.4 mmol) was dissolved in 80% HOAc (900 mL) at25° C. The mixture was stirred at 25° C. overnight. The reaction wasquenched with MeOH, and the solvent was removed to give the alcohol(42.1 g, 70%) as a white foam. To a solution of the alcohol (42.1 g,92.6 mmol) in anhydrous CH₃CN (300 mL) was added IBX (28.5 g, 121.7mmol) at 25° C. The reaction mixture was refluxed for 1 hour and thencooled to 0° C. The precipitate was filtered-off, and the filtrate wasconcentrated to give 58-3 (39.2 g, 93%) as a yellow solid.

Preparation of (58-4):

To a solution of 58-3 (39.2 g, 86.39 mmol) in 1,4-dioxane (250 mL) wasadded 37% CH₂O (28.1 mL, 345.6 mmol) and 2N NaOH aqueous solution (86.4mL, 172.8 mmol). The mixture was stirred at 25° C. for 2 h and thenneutralized with AcOH to pH=7. To the reaction were added EtOH (200 mL)and NaBH₄ (19.7 g, 518.6 mmol). The mixture was stirred at 25° C. for 30mins. The reaction was quenched with saturated aqueous NH₄Cl. Themixture was extracted with EA, and the organic layer was dried overNa₂SO₄ and concentrated. The residue was purified by silica gel columnchromatography (PE:EA=4:1 to 2:1) to give the diol derivative (25.5 g,55%) as a white solid. To a stirred solution of the diol derivative(25.5 g, 52.5 mmol) in anhydrous pyridine (150 mL) and anhydrous CH₃CN(150 mL) was added BzCl (6.6 g, 52.47 mmol) dropwise at 0° C. Themixture was then stirred at 25° C. for 14 h. The reaction was quenchedwith H₂O, and the solution was concentrated. The residue was dissolvedin EA and washed with NaHCO₃. The organic layer was dried over Na₂SO₄and concentrated. The residue was purified on a silica gel column(PE/EA=5:4) to give 58-4 (18.1 g, 60%) as a white foam.

Preparation of (58-5):

Cs₂CO₃ (30.0 g, 92.0 mmol) and BnBr (10.4 g, 61.3 mmol) were added to astirred solution of compound 58-4 (18.1 g, 30.6 mmol) in anhydrous DMF(300 mL), and stirring was continued at 25° C. overnight. The reactionwas quenched with NH₄Cl, extracted with EA and washed with brine. Thesolvent was removed to give the Bz protected derivative (19.3 g, 95%) asa light yellow solid. To a stirred solution of the Bz protectedderivative (19.3 g, 28.4 mmol) in anhydrous MeOH (230 mL) was addedNaOMe (24.9 g, 460 mmol) at 25° C. for 1 h. The reaction was quenchedwith AcOH (10 mL) and concentrated. The residue was purified on a silicagel column (PE/EA=1/2) to afford 58-5 (11.2 g, 54%) as a white solid.

Preparation of (58-6):

To a stirred solution of 58-5 (200 mg, 0.347 mmol) in anhydrous DCM (5mL) was added DMP (168 mg, 0.674 mmol) at 25° C. The mixture was stirredat 25° C. for 2 h. The solvent was removed, and the residue was purifiedon a silica gel column (PE:EA=5:1 to 1:1) to give the aldehydederivative (161 mg, 81%). To a stirred solution of the aldehydederivative (200 mg, 0.348 mmol) in anhydrous THF (5 mL) was added MeMgBr(1.0 mL, 1.01 mmol) at −78° C. The mixture was stirred at −78° C. for 1h. The reaction was quenched with NH₄Cl and extracted with EA. Theconcentrated organic phase was purified by column chromatography(PE:EA=5:1 to 1:1) to give 58-6 (135 mg, 65%).

Preparation of (58-7):

To a solution of 58-6 (900 mg, 1.5 mmol) in DCM was added DMP (2.5 g,6.0 mmol) at 0° C. After stirring at 0° C. for 1 h, the mixture wasquenched with Na₂S₂O₃. The solvent was removed, and the residue waspurified on a silica gel column (PE:EA=5:1 to 1:1) to give the ketonederivative (700 mg, 78%). To a solution of the ketone derivative (700mg, 1.52 mmol) in MeOH was added NaBH₄ in portions. After stiffing atthe same temperature for 1 h, the mixture was quenched with water. Thesolvent was removed, and the residue was purified on a silica gel column(PE:EA=5:1 to 1:1) to give 58-7 (500 mg, 71%).

Preparation of (58-8):

To a stirred solution of DAST (1.39 g, 8.68 mmol) in anhydrous toluene(15 mL) was added dropwise a solution of 58-6 (1.0 g, 1.73 mmol) at −78°C. The mixture was stirred at −78° C. for 30 min. The solution waswarmed to 25° C. slowly and stirring continued overnight. The mixturewas poured into a saturated Na₂CO₃ solution. The concentrated organicphase was purified on a silica gel column (PE:EA=10:1 to 4:1) to givethe fluoride derivative (449 mg, 45%). A mixture of the fluoridederivative (1.20 g, 2.07 mmol) and CAN (3.41 g, 6.23 mmol) in a 3:1solution of MeCN and water (10 mL) was stirred at 25° C. overnight.Brine (10 mL) was added, and the mixture extracted with EA. The combinedorganic extracts were dried and evaporated under reduced pressure.Purification by chromatography on silica with PE:EA=10:1 to 2:1 gave58-8 as a yellow solid (475 mg, 50%).

Preparation of (58-9):

To a stirred solution of 58-8 (550 mg, 210 mmol) in anhydrous MeCN (10mL) were added TPSCl (725 mg, 2.40 mmol), DMAP (293 mg, 2.40 mmol) andTEA (242 mg, 2.40 mmol) at 25° C. The mixture was stirred at 25° C.overnight. NH₄OH (25 mL) was added and stirred for 2 h. The solvent wasremoved, and the residue was purified on a silica gel column(DCM:MeOH=10:1) to give 58-9 (300 mg). ¹H NMR (CD₃OD, 400 MHz) δ 7.70(d, J=8.4 Hz, 1H), 7.25-7.36 (m, 10H), 6.13 (dd, J=2.8, 16.8 Hz, 1H),5.40 (d, J=7.6 Hz, 1H), 5.15 (m, 1H), 4.81 (d, J=11.6 Hz, 1H), 4.40-4.52(m, 4H), 3.82 (d, J=8.8 Hz, 7H), 3.62 (d, J=9.6 Hz, 7H), 1.35 (dd,J=2.8, 14.4 Hz, 3H). ESI-MS: m/z 472.1 [M+H]⁺.

Preparation of (58a):

A 1 M boron trichloride solution in CH₂Cl₂ (3.2 mL; 3.2 mmol) was addeddropwise to a solution of 58-9 (200 mg, 0.42 mmol) in anhydrous CH₂Cl₂(10 mL) at −78° C. The mixture was slowly (in 4 h) warmed to −30° C. andstirred at −30 to −20° C. for 3 h. Ammonium acetate (1 g) and MeOH (5mL) were added, and the resulting mixture allowed to warm to ambienttemperature. The solvent was removed, and residue purified by RP-HPLC(0-60% B; A: 50 mM aqueous TEAA, B: 50 mM TEAA in MeOH) to yield 58a (75mg). ¹H NMR (CD₃OD) δ 7.97 (d, 1H), 6.20 (dd, 1H), 5.92 (d, 1H), 5.22(dt, 1H), 4.98 (dq, 1H), 4.58 (dd, 1H), 3.73 (m, 2H), 1.40 (dd, 3H). ¹⁹FNMR (CD₃OD) δ −205.80 (m, 1F), −188.54 (m, 1F). ESI-MS: m/z 290.4[M−H]⁻.

Example 56 Preparation of Compound (59a)

Preparation of (59-2):

To a solution of 59-1 (100.0 g, 406.5 mmol) in pyridine (750 mL) wasadded DMTrCl (164.9 g, 487.8 mmol). The solution was stirred at R.T. for15 h. MeOH (300 mL) was added, and the mixture was concentrated todryness under reduced pressure. The residue was dissolved in EtOAc andwashed with water. The organic layer was dried over Na₂SO₄ andconcentrated. The residue was dissolved in DCM (500 mL). To thissolution were added imidazole (44.3 g, 650.4 mmol) and TBSCl (91.9 g,609.8 mmol). The resulting reaction mixture was stirred at R.T. for 14h. The reaction solution was washed with NaHCO₃ and brine. The organiclayer was dried over Na₂SO₄, and concentrated to give the crude productas a light yellow solid. The crude product (236.4 g, 356.6 mmol) wasdissolved in 80% HOAc aqueous solution (500 mL). The mixture was stirredat R.T. for 15 h. The mixture was diluted with EtOAc, washed with NaHCO₃solution and brine. The organic layer was dried over Na₂SO₄ and purifiedon a silica gel column chromatography (1-2% MeOH in DCM) to give 59-2(131.2 g, 89.6%) as a light yellow solid. ¹H NMR (DMSO-d6, 400 MHz) δ11.39 (s, 1H), 7.88 (d, J=7.2 Hz, 1H), 5.89 (dd, J=18.0 Hz, J=2.0 Hz,1H), 5.64 (d, J=8.0 Hz, 1H), 5.21 (dd, J₁=J₂=7.2 Hz, 1H), 5.18-5.03 (m,1H), 4.37-4.29 (m, 1H), 3.86 (dd, J=3.2 Hz, J=3.2 Hz, 3H), 3.78-3.73 (m,1H), 3.51-3.56 (m, 1H), 3.31 (s, 1H), 0.89 (s, 9H), 0.11 (s, 6H);ESI-MS: m/z 802 [M+H]⁺.

Preparation of (59-3):

To a solution of 59-2 (131.2 g, 364.0 mmol) in anhydrous CH₃CN (1200 mL)was added IBX (121.2 g, 432.8 mmol) at R.T. The reaction mixture wasrefluxed for 3 h and then cooled to 0° C. The precipitate wasfiltered-off, and the filtrate was concentrated to give the crudealdehyde (121.3 g) as a yellow solid. The aldehyde was dissolved in1,4-dioxane (1000 mL). 37% CH₂O (81.1 mL, 1.3536 mol) and 2M NaOHaqueous solution (253.8 mL, 507.6 mmol) were added. The mixture wasstirred at R.T. for 2 h and then neutralized with AcOH to pH=7. To thesolution were added EtOH (400 mL) and NaBH₄ (51.2 g, 1.354 mol). Themixture was stirred at R.T. for 30 mins and quenched with sat. aqueousNH₄Cl. The mixture was extracted with EA. The organic layer was driedover Na₂SO₄ and concentrated. The residue was purified by silica gelcolumn chromatography (1-3% MeOH in DCM) to give 59-3 (51.4 g, 38.9%) asa white solid.

Preparation of (59-4):

To a solution of 59-3 (51.4 g, 131.6 mmol) in anhydrous DCM (400 mL)were added pyridine (80 mL) and DMTrCl (49.1 g, 144.7 mmol) at 0° C. Thereaction was stirred at R.T. for 14 h, and then treated with MeOH (30mL). The solvent was removed, and the residue was purified by silica gelcolumn chromatography (1-3% MeOH in DCM) to give the mono-DMTr protectedintermediate as a yellow foam (57.4 g, 62.9%). To the mono-DMTrprotected intermediate (57.4 g, 82.8 mmol) in CH₂Cl₂ (400 mL) was addedimidazole (8.4 g, 124.2 mmol) and TBDPSCl (34.1 g, 124.2 mmol). Themixture was stirred at R.T. for 14 h. The precipitated was filtered off,and the filtrate was washed with brine and dried over Na₂SO₄. Thesolvent was removed to give the residue (72.45 g) as a white solid,which was dissolved in 80% HOAc aqueous solution (400 mL). The mixturewas stirred at R.T. for 15 h. The mixture was diluted with EtOAc, washedwith NaHCO₃ solution and brine. The organic layer was dried over Na₂SO₄and purified by silica gel column chromatography (1-2% MeOH in DCM) togive 59-4 (37.6 g, 84.2%) as a white solid. ¹H NMR (CD₃OD, 400 MHz) δ7.76 (d, J=4.0 Hz, 1H), 7.70 (dd, J=1.6 Hz, J=8.0 Hz, 2H), 7.66-7.64 (m,2H), 7.48-7.37 (m, 6H), 6.12 (dd, J=2.8 Hz, J=16.8 Hz, 1H), 5.22 (d,J=8.0 Hz, 1H). 5.20-5.05 (m, 1H), 4.74 (dd, J=5.6 Hz, J=17.6 Hz, 1H),4.16 (d, J=12.0 Hz, 1H), 3.87-3.80 (m, 2H), 3.56 (d, J=12.0 Hz, 1H),1.16 (s, 9H), 0.92 (s, 9H), 0.14 (s, 6H).

Preparation of (59-5):

To a solution of 59-4 (3.0 g, 4.78 mmol) in anhydrous DCM (100 mL) wasadded Dess-Martin periodinane (10.4 g, 23.9 mmol) at 0° C. undernitrogen. The reaction mixture was stirred at R.T. for 5 h. The mixturewas poured into NaHCO₃ and Na₂S₂O₃ (1:1) aqueous solution. The organiclayer was dried over anhydrous Na₂SO₄ and concentrated to give aresidue. The residue was purified on a silica gel column (20% EtOAc inPE) to give the intermediate (2.5 g, 83.1%) as a white solid.

To a mixture of bromotriphenyl(propyl)phosphorane (6.45 g, 16.8 mmol) inanhydrous THF (3 mL) was added t-BuOK (16.8 mL, 16.8 mmol) at 0° C.under nitrogen. The reaction mixture was stirred at 0° C. for 50 mins. Asolution of the above intermediate (1.5 g, 2.4 mmol) in anhydrous THF (3mL) was added dropwise at 0° C. under nitrogen. The reaction mixture wasstirred at R.T. for 3 h. The reaction was quenched by NH₄Cl aqueoussolution and extracted with EtOAc. The organic layer was dried overanhydrous Na₂SO₄ and concentrated to give a residue. The residue waspurified on a silica gel column (20% EtOAc in PE) to give 59-5 (1.3 g,83%) as a white solid.

Preparation of (59a):

To a solution of 59-5 (300 mg, 0.45 mmol) in anhydrous CH₃CN (2 mL) wereadded TPSCl (341 mg, 1.13 mmol), DMAP (138 mg, 1.13 mmol) and NEt₃ (571mg, 5.65 mmol) at R.T. The reaction mixture was stirred at R.T. for 2 h.NH₄OH (1 mL) was added, and the reaction mixture was stirred for 1 h.The mixture was diluted with EA and washed with water. The organic layerwas dried and concentrated to give a residue. The residue was purifiedon a silica gel column (2% MeOH in DCM) to give the cytidine derivative(285 mg, 95.0%) as a white solid.

To a solution of the cytidine derivative (280 mg, 0.43 mmol) in MeOH (10mL) was added NH₄F (1.0 g) at R.T. The reaction mixture was refluxed for12 h. The mixture was filtered, and the filtrate was concentrated. Theresidue was purified on a silica gel column (10% MeOH in DCM) to give59a (81 mg, 61%) as a white solid. ¹H NMR (CD₃OD, 400 MHz) δ 8.11 (d,J=8.0 Hz, 1H), 5.91 (dd, J=1.2 Hz, J=17.6 Hz, 1H), 5.90 (d, J=7.6 Hz,1H), 5.57-5.59 (m, 2H), 4.82-4.96 (m, 1H), 4.42 (dd, J=4.8 Hz, J=24.4Hz, 1H), 3.72 (d, J=12.4 Hz, 1H) 3.58 (d, J=12.4 Hz, 1H), 2.31-2.41 (m,2H), 0.99 (t, J=7.6 Hz, 3H). ESI-TOF-MS: m/z 300.1 [M+H]⁺.

Example 57 Preparation of Compound (60a)

Preparation of (60-1):

To a solution of 59-5 (450 mg, 0.69 mmol) in MeOH (10 mL) was added Pd/C(200 mg) at R.T. The reaction mixture was stirred R.T. for 1 h under H₂(balloon). The mixture was filtered, and the filtrate was concentratedto give crude 60-1 (440 mg, 97.1%) as a white solid.

Preparation of (60a):

To a solution of 60-1 (440 mg, 0.67 mmol) in anhydrous CH₃CN (2 mL) wereadded TPSCl (510 mg, 1.68 mmol), DMAP (205 mg, 1.68 mmol) and NEt₃ (338mg, 3.35 mmol) at R.T. The reaction mixture was stirred at R.T. for 2 h.NH₄OH (1 mL) was added, and the reaction was stirred for 1 h. Themixture was diluted with EA and washed with water. The solvent wasremoved. The crude product was purified on a silica gel column (2% MeOHin DCM) to give the cytidine derivative (205 mg, 46.5%) as a whitesolid.

To a solution of the cytidine derivative (205 mg, 0.31 mmol) in MeOH (6mL) was added NH₄F (0.6 g) at R.T. The reaction mixture was refluxedovernight. After cooling to R.T., the mixture was filtered. The filtratewas concentrated, and the residue was purified on a silica gel column(10% MeOH in DCM) to give 60a (59 mg, 62.8%) as a white solid. ¹H NMR(CD₃OD, 400 MHz) δ 8.09 (d, J=7.6 Hz, 1H), 6.01 (dd, J=3.2 Hz, J=15.6Hz, 1H), 5.89 (d, J=7.2 Hz, 1H), 4.95-5.12 (m, 1H), 4.41 (dd, J=5.2 Hz,J=17.2 Hz, 1H), 3.75 (d, J=12.0 Hz, 1H) 3.56 (d, J=11.6 Hz, 1H),1.73-1.80 (m, 1H), 1.55-1.63 (m, 1H), 1.40-1.46 (m, 4H), 0.92 (t, J=7.6Hz, 3H). ESI-MS: m/z 301.8 [M+H]⁺.

Example 58 Preparation of Compound (61a)

Preparation of (61-1):

To a solution of 59-4 (1.5 g, 2.39 mmol) in anhydrous DCM (100 mL) wasadded Dess-Martin periodinane (5.2 g, 11.95 mmol) at 0° C. undernitrogen. The reaction mixture was stirred at R.T. for 5 h. The mixturewas poured into NaHCO₃ and Na₂S₂O₃ solution and washed with brine. Theorganic layer was dried with anhydrous Na₂SO₄, and concentrated to givethe crude intermediate (1.5 g) as a white solid.

To a solution of the crude intermediate (1.5 g, 2.39 mmol) in THF (12mL) was added methylmagnesium bromide (2.4 mL, 7.2 mmol) dropwise at 0°C. The resulting mixture was stirred at 0° C. for 2 h. After thestarting material was consumed, the reaction was quenched with saturatedNH₄Cl. The reaction mixture was extracted with DCM. The organic layerwas washed with brine, dried and concentrated to give crude 61-1 (1.5g).

Preparation of (61-2):

To a solution of 61-1 (1.5 g, 2.39 mmol) in anhydrous DCM (50 mL) wasadded Dess-Martin periodinane (4.5 g, 10.6 mmol). The reaction mixturewas stirred at R.T. overnight. The mixture was poured into NaHCO₃ andNa₂S₂O₃ aqueous solution. The organic layer was separated, washed withbrine, dried and concentrated to give a residue. The residue waspurified on a silica gel column (10% EtOAc in PE) to give theintermediate (907 mg, 58.6%) as a white solid.

To a mixture of bromo(methyl)triphenylphosphorane (5.0 g, 14 mmol) inanhydrous THF (8 mL) was added t-BuOK (12.6 mL, 12.6 mmol) at 0° C.under nitrogen. The mixture was stirred at R.T. for 50 mins. A solutionof the above intermediate (900 mg, 1.4 mmol) in anhydrous THF (4 mL) wasadded dropwise at 0° C. under nitrogen. The reaction mixture was stirredat R.T. for 3 h. The reaction mixture was quenched with NH₄Cl aqueoussolution and extracted with DCM. The organic layer was separated, washedwith brine, dried and concentrated to give a residue. The residue waspurified on a silica gel column (5% EtOAc in PE) to give 61-2 (700 mg,78.0%) as a white solid.

Preparation of (61a):

To a solution of 61-2 (298 mg, 0.46 mmol) in anhydrous CH₃CN (5.5 mL)were added TPSCl (346.5 mg, 1.14 mmol), DMAP (139.6 mg, 1.14 mmol) andNEt₃ (115.6 mg, 1.14 mmol) at R.T. The reaction mixture was stirred atR.T. for 2 h. NH₄OH (1 mL) was added, and the mixture was stirred foranother 1 h. The mixture was diluted with DCM and washed with water. Theorganic layer was separated, washed with brine, dried and concentratedto give a residue. The residue was purified on a silica gel column (2%MeOH in DCM) to give the cytidine derivative (250 mg, 85.0%) as a whitesolid.

To a solution of the cytidine derivative (250 mg, 0.39 mmol) in MeOH (10mL) was added NH₄F (1.0 g) at R.T. The reaction was refluxed for 12 h.The mixture was filtered, and the filtrate was concentrated. The residuewas purified on a silica gel column (10% MeOH in DCM) to give 61a (55mg, 49%) as a white solid. ¹H NMR (CD₃OD, 400 MHz) δ 8.11 (d, J=7.6 Hz,1H), 6.21 (dd, J=4.2 Hz, J=14.0 Hz, 1H), 5.91 (d, J=7.6 Hz, 1H), 5.10(dt, J=4.8 Hz, J=53.6 Hz, 1H), 5.13 (brs, 1H), 5.00 (brs, 1H), 4.46 (dd,J=4.8 Hz, J=11.6 Hz, 1H), 3.83 (d, J=11.6 Hz, 1H), 3.54 (d, J=11.6 Hz,1H), 1.84 (s, 3H). ESI-MS: m/z 285.9 [M+H]±.

Example 59 Preparation of Compound (62a)

Preparation of (62-1):

To a solution of 61-2 (400 mg, 0.63 mmol) in MeOH (10 mL) was added Pd/C(400 mg) at R.T. The reaction was stirred at R.T. for 5 h under H₂(balloon). The mixture was filtered, and the filtrate was concentratedto give crude 62-2 (350 mg, 87%) as a white solid.

Preparation of (62a):

To a solution of 62-1 (350 mg, 0.55 mmol) in anhydrous CH₃CN (6 mL) wereadded TPSCl (414 mg, 1.4 mmol), DMAP (166.8 mg, 1.4 mmol) and NEt₃(138.1 mg, 1.4 mmol) at R.T. The reaction mixture was stirred at R.T.for 2 h. NH₄OH (1 mL) was added, and the reaction was stirred foranother 1 h. The mixture was diluted with EA and washed with water. Theorganic layer was separated, dried and concentrated to give a residue.The residue was purified on a silica gel column (2% MeOH in DCM) to givethe cytidine derivative (300 mg, 85%) as a white solid.

To a solution of the cytidine derivative (300 mg, 0.47 mmol) in MeOH (10mL) was added NH₄F (1.5 g) at R.T. The reaction mixture was refluxedovernight. After cooling to R.T., the mixture was filtered. The filtratewas concentrated. The crude product was purified on a silica gel column(10% MeOH in DCM) to give 62a (83 mg, 61%) as a white solid. ¹H NMR(CD₃OD, 400 MHz) δ 8.12 (d, J=7.6 Hz, 1H), 6.22 (dd, J=6.4 Hz, J=12.4Hz, 1H), 5.94 (d, J=7.6 Hz, 1H), 5.25 (dt, J=5.6 Hz, J=54.0 Hz, 1H),4.38 (t, J=4.8 Hz, 1H), 3.72 (d, J=11.6 Hz, 1H), 3.67 (d, J=11.6 Hz,1H), 2.31-2.42 (m, 1H), 0.99 (2d, J=7.2 Hz, 6H). ESI-MS: m/z 287.8[M+H]⁺.

Example 60 Preparation of Compound (63a)

Preparation of (63-2):

To a solution of 63-1 (50 g, 203 mmol) in anhydrous pyridine (200 mL)was added TBDPS-Cl (83.7 g, 304 mmol). The reaction was allowed toproceed overnight at R.T. The solution was concentrated under reducedpressure to give a residue. The residue was partitioned between ethylacetate and water. The organic layer was separated, washed with brine,dried over magnesium sulfate and concentrated under reduced pressure togive 5′-OTBDPS ether as a white foam (94 g).

To a solution of the 5′-OTBDPS ether (94.0 g, 194.2 mmol) in anhydrousDCM (300 mL) were added silver nitrate (66.03 g, 388.4 mmol) andcollidine (235 mL, 1.94 mol). The mixture was stirred at R.T. After mostof silver nitrate was dissolved (˜15 min), the mixture was cooled to 0°C. Monomethoxytrityl chloride (239.3 g, 776.8 mmol) was added as asingle portion, and the mixture was stirred overnight at R.T. Themixture was filtered through Celite, and the filtrate was diluted withMTBE. The solution was washed successively with 1M citric acid, dilutedbrine and 5% sodium bicarbonate. The organic solution was dried oversodium sulfate and concentrated under vacuum to give the fully protectedintermediate as a yellow foam.

The fully protected intermediate was dissolved in toluene (100 mL), andthe solution was concentrated under reduced pressure. The residue wasdissolved in anhydrous THF (250 mL) and treated with TBAF (60 g, 233mmol). The mixture was stirred for 2 hours at R.T., and the solvent wasremoved under reduced pressure. The residue was taken into ethylacetate, and the solution was washed with saturated sodium bicarbonateand brine. After drying over magnesium sulfate, the solvent was removedin vacuum. The residue was purified by column chromatography (PE:EA=5:1,1:1) to give 63-2 (91 g, 86.4%) as a white foam.

Preparation of (63-3):

To a solution of 63-2 (13.5 g, 26 mmol) in DCM (100 mL) was addedpyridine (6.17 mL, 78 mmol). The solution was cooled to 0° C. andDess-Martin periodinane (33.8 g, 78 mmol) was added as a single portion.The reaction mixture was stirred for 4 h at R.T. The reaction wasquenched with Na₂S₂O₃ solution (4%) and sodium bicarbonate aqueoussolution (4%) (the solution was adjusted to pH 6, ˜150 mL). The mixturewas stirred for 15 min. The organic layer was separated, washed withdiluted brine and concentrated under reduced pressure. The residue wasdissolved in dioxane (100 mL), and the solution was treated with 37%aqueous formaldehyde (21.2 g, 10 eq) and 2N aqueous sodium hydroxide (10eq). The reaction mixture was stirred at R.T. overnight. After stiffingfor 0.5 h at R.T., the excess of aqueous sodium hydroxide wasneutralized with saturated with NH₄Cl (˜150 mL). The mixture wasconcentrated under reduced pressure. The residue was partitioned betweenethyl acetate and 5% sodium bicarbonate. The organic phase wasseparated, washed with brine, dried over magnesium sulfate andconcentrated. The residue was purified by column chromatography (MeOH:DCM=100:1-50:1) to give 63-3 (9.2 g, 83.6%) as a white foam.

Preparation of (63-4):

63-3 (23 g, 42.0 mmol) was co-evaporated with toluene twice. The residuewas dissolved in anhydrous DCM (250 mL) and pyridine (20 mL). Thesolution was cooled to −35° C. Triflic anhydride (24.9 g, 88.1 mmol) wasadded dropwise over 10 mins. The reaction was stirring for 40 min at−35° C. When TLC (PE:EA=2:1 and DCM:MeOH=15:1) showed that the reactionwas complete, the reaction was quenched with water (50 mL) at 0° C. Themixture was stirred 30 mins, extracted with EA. The organic phase wasdried over Na₂SO₄ and filtered through a silica gel pad. The filtratewas concentrated under reduced pressure. The residue was purified bycolumn chromatography (PE:EA=100:1-1:1) to give 63-4 (30.0 g, 88.3%) asa brown foam.

Preparation of (63-5):

63-4 (30 g, 36.9 mmol) was co-evaporated twice with toluene. Theresulting bis-triflate was dissolved in anhydrous DMF (150 mL), cooledto 0° C. and treated with sodium hydride (60% in mineral oil; 1.5 g,40.6 mmol, 1.1 eq). The reaction mixture was stirred at R.T. for 1 huntil TLC (DCM:MeOH=15:1) showed the disappearance of the bis-triflateand formation of the 2,5′-anhydro intermediate. Lithium chloride (4.6 g,110.7 mmol, 3 eq) was added, and the stirring was continued for 2 h. Themixture was taken into 100 mL of half saturated ammonium chloride andethyl acetate. The organic phase was separated, washed with dilutedbrine and concentrated under reduced pressure to give 63-5.

Preparation of (63-6):

63-5 was dissolved in THF (150 mL), and the solution was treated with 1Naqueous sodium hydroxide (˜41 mL, 40.1 mmol, 1.1 eq). The mixture wasstirred at R.T. for 1 h. The reaction was monitored by LCMS. Thereaction was diluted with half saturated sodium bicarbonate (˜60 mL) andextracted with ethyl acetate. The organic phase was dried (magnesiumsulfate) and concentrated under reduced pressure. Purification of theresidue by column chromatography (DCM:MeOH=300:1-60:1) gave 63-6 (18.3g, 87.6%) as a yellow foam.

Preparation of (63-7):

To a solution of 63-6 (18.3 g, 32.33 mmol) in anhydrous DCM (150 mL) wasadded TBS-Cl (17.7 g, 64.6 mmol) and imidazole (6.6 g, 97 mmol). Thereaction was allowed to proceed overnight at R.T. The reaction wasdiluted with water and extracted with DCM. The organic layer wasseparated, washed with brine, dried over Na₂SO₄ and concentrated.Purification of the residue by column chromatography(DCM:MeOH=300:1˜80:1) gave 63-7 (18.4 g, 83.7%) as a white foam.

Preparation of (63-8):

A solution of 63-7 (18.4 g, 27.1 mmol), DMAP (6.6 g, 54.0 mmol) and TEA(5.4 g, 54.0 mmol) in MeCN (450 mL) was treated with2,4,6-triispropylbenzenesulfonyl chloride (TPSCl, 16.3 g, 54.0 mmol).The mixture was stirred at R.T. for 3 h. NH₃H₂O (70 mL) was added, andthe mixture was stirred for 2 h. The solution was evaporated underreduced pressure, and the residue was purified on a silica gel column(DCM:MeOH=100:1 to 15:1) to give 63-8 (18.0 g) as a light yellow solid.

Preparation of (63-9):

To a solution of 63-8 (18.0 g, 26.5 mmol) in anhydrous DCM (150 mL) wasadded collidine (8.1 g, 66.3 mmol, 2.5 eq), silver nitrate (4.5 g, 26.5mmol, 1.0 eq) and DMTrCl (13.4 g, 39.7 mmol, 1.5 eq). The reaction wasallowed to proceed overnight at R.T. The mixture was filtered. Thefiltrate was washed with brine and extracted with DCM. The organic layerwas separated, dried over Na₂SO₄ and concentrated. The residue waspurified by column chromatography (PE:EA=60:1˜3:1) as a yellow foam. Thefoam was dissolved in THF (150 mL), and TBAF (10.4 g, 39.7 mmol, 1.5 eq)was added. The reaction was allowed to proceed overnight at R.T. Themixture was concentrated, washed with brine and extracted with EA. Theorganic layer was separated, dried over Na₂SO₄ and concentrated.Purification of the residue by column chromatography (PE:EA=60:1˜EA)gave 63-9 (21.3 g, 92.4%) as a yellow foam.

Preparation of (63-10):

To a solution of 63-9 (2.0 g, 2.3 mmol) in anhydrous DCM (20 mL) wasadded Dess-Martin periodinane (1.95 g, 4.6 mmol) at 0° C. undernitrogen. The reaction was stirred at R.T. for 5 h. The mixture wasdiluted with EtOAc (100 mL) and washed with a mixture of saturatedaqueous Na₂S₂O₃ and saturated aqueous NaHCO₃. The crude product waspurified by column chromatography on silica gel (PE:EtOAc=2:1) to give63-10 (1.8 g, 90%) as a yellow solid.

Preparation of (63-11):

To a solution of tetramethyl methylenediphosphonate (390 mg, 1.68 mmol)in anhydrous THF (10 mL) was added NaH (84 mg, 2.1 mmol) at 0° C. undernitrogen. The reaction was stirred at 0° C. for 30 min. A solution of63-10 (1.2 g, 1.4 mmol) in anhydrous THF (10 mL) was added dropwise at0° C. The reaction mixture was stirred at R.T. for 1 h. The reaction wasquenched by saturated aqueous NH₄Cl, and the crude product was purifiedby column chromatography on silica gel (DCM:MeOH=150:1) to give 63-11(1.2 g, 88.2%) as a yellow solid. ¹H NMR (DMSO-d6, 400 MHz) δ 8.51 (s,1H), 7.46-7.09 (m, 22H), 6.88-6.82 (m, 6H), 6.62 (q, J₁=17.2 Hz, J₂=22.4Hz, 1H), 6.12 (d, J=7.2 Hz, 1H), 5.86-5.75 (m, 2H), 5.43 (d, J=25.2 Hz,1H), 4.63 (dd, J=4.8 Hz, J=21.2 Hz, 1H), 4.45 (d, J=12.0 Hz, 1H), 3.94(d, J=12.0 Hz, 1H), 3.72 (s, 9H), 3.53 (q, J=11.2 Hz, J=16.0 Hz, 6H).ESI-MS: m/z 971.59 [M+H]⁺.

Preparation of (63a):

A solution of 63-11 (1.0 g, 1.03 mmol) in 80% HOAc (46 mL) was stirredat 80-90° C. for 2 h. The solvent was removed, and the crude product waspurified by column chromatography on silica gel (DCM:MeOH=20:1) to givean intermediate (337 mg, 82.3%) as a white solid. The intermediate wasdissolved in MeOH and wet Pd/C (300 mg) was added. The reaction mixturewas stirred under H₂ (1 atm) for 1 h and then filtered. The solvent wasremoved, and the residue was purified on a silica gel column(DCM:MeOH=20:1) to give 63a (192 mg, 63.9%) as a white solid. ¹H NMR(CD₃OD, 400 MHz) δ 7.60 (d, J=7.6 Hz, 1H), 5.87 (d, J=7.2 Hz, 1H), 5.70(dd, J=2.0 Hz, J=21.6 Hz, 1H), 5.31 (m, 1H), 4.67 (dd, J=5.6 Hz, J=19.6Hz, 1H), 3.80 (m, 2H), 3.75 (2d, J=2.4 Hz, 6H), 1.92-2.20 (m, 4H). ³¹PNMR (CD₃OD, 162 MHz) δ 35.77. ESI-MS: m/z 400.0 [M+H]⁺.

Example 61 Preparation of Compound (64a)

Preparation of (64-2):

To a solution of 64-1 (1.0 g, 4.3 mmol) in THF (20 mL) was added NaH(120 mg, 3.0 mmol), and the reaction mixture was stirred at 0° C. for 1h. Selectfluor (1.2 g, 3.4 mmol) was added into the reaction mixture.The crude product was purified on a silica gel column and eluted with EAto give 64-2 (500 mg, 57%) as a white solid. ¹H NMR (CD₃OD, 400 MHz) δ5.65 (dt, J=14.0 Hz, J=44.8 Hz, 1H), 3.90 (d, J=9.6 Hz, 12H).

Preparation of (64-3):

To a solution of compound 64-2 (390 mg, 1.68 mmol) in anhydrous THF (10mL) was added NaH (84 mg, 2.1 mmol) at 0° C. under nitrogen. Thereaction mixture was stirred at 0° C. for 30 mins. A solution of 63-10(1.2 g, 1.4 mmol) in anhydrous THF (10 mL) was added dropwise at 0° C.The reaction mixture was stirred at R.T. for 1 h. The reaction wasquenched with saturated aqueous NH₄Cl and concentrated to give aresidue. The residue was purified on a silica gel column(DCM:MeOH=150:1) to give crude 64-3 (1.2 g, 88.2%) as a yellow solid.

Preparation of (64a):

A solution of crude 64-3 (230 mg, 0.23 mmol) in 80% HOAc (3 mL) wasstirred at 80-90° C. for 2 h. The crude product was purified on a silicagel column (eluted with DCM:MeOH=20:1) to give 64a (54 mg, 53.7%) as awhite solid. ¹H NMR (DMSO, 400 MHz) δ 7.69 (d, J=7.2 Hz, 1H), 7.37 (d,J=1.6 Hz, 2H), 6.62-6.78 (m, 1H), 6.40 (d, J=5.6 Hz, 1H), 6.03-6.07 (m,1H), 5.77 (d, J=7.6 Hz, 1H), 5.61-5.64 (m, 1H), 5.48-5.51 (m, 1H),4.60-4.64 (m, 1H), 4.38 (d, J=11.6 Hz, 1H), 3.98 (d, J=11.6 Hz, 1H),3.75 (2d, J=11.6 Hz, 6H). ESI-MS: m/z 416.3 [M+H]⁺.

Example 62 Preparation of Compound (65a)

A solution of crude 64-3 (230 mg, 0.23 mmol) in 80% HOAc (3 mL) wasstirred at 80-90° C. for 2 h. The crude product was purified on a silicagel column (eluted with DCM:MeO=20:1) to give 64a (52 mg, 33.7%) as awhite solid. ¹H NMR (DMSO, 400 MHz) δ 7.59 (d, J=7.2 Hz, 1H), 7.32 (s,2H), 6.25-6.28 (m, 1H), 5.86-6.02 (m, 2H), 5.73 (s, 1H), 5.31 (d, J=14.0Hz, 1H), 4.72 (d, J=16.4 Hz, 1H), 3.90 (d, J=10.0 Hz, 1H), 3.73 (2d,J=11.6 Hz, 6H).

Example 63 Preparation of Compound (66a)

A solution of 64a (130 mg, 0.3 mmol) in EA:MeOH (5:1, 20 mL) was stirredunder H₂ (15 Psi) at R.T. for 2 h. The reaction mixture was filtered andconcentrated to give a residue. The residue was purified on a silica gelcolumn (DCM:MeOH, 20:1) to give 66a (70 mg, 54%) as a white solid. ¹HNMR (DMSO, 400 MHz) δ 7.61 (d, J=7.2 Hz, 1H), 5.87 (d, J=7.2 Hz, 1H),5.58-5.80 (m, 1H), 5.26-5.47 (m, 2H), 4.97-5.03 (m, 1H), 5.58-5.80 (m,1H), 3.73-3.94 (m, 6H), 2.33-2.59 (m, 2H). ESI-MS: m/z 418.3 [M+H]⁺.

Example 64 Preparation of Compound (67a)

Preparation of (67-2):

To a solution of 67-1 (2.0 g, 6.9 mmol) in THF (20 mL) was added NaH(110 mg, 2.8 mmol), and the reaction mixture was stirred at 0° C. for 1h. Selectfluor (5.0 g, 13.6 mmol) was added into the reaction mixture.The reaction was quenched with saturated NH₄Cl and extracted with EA.The organic layer was separated, dried and concentrated to give thecrude product. The crude product was purified on a silica gel column(eluted with EA) to give 67-2 (600 mg, 28.3%) as a white solid. ¹H NMR(CD₃OD, 400 MHz) δ 5.65 (dt, J=14.0 Hz, J=44.8 Hz, 1H), 4.24-4.46 (m,8H), 1.35-1.39 (m, 12H).

Preparation of (67-3):

To a solution of 67-2 (2.14 g, 7.0 mmol) in anhydrous THF (10 mL) wasadded NaH (84 mg, 2.1 mmol) at 0° C. under nitrogen. The reactionmixture was stirred at 0° C. for 30 mins. A solution of 63-10 (3.0 g,3.5 mmol) in anhydrous THF (10 mL) was added in dropwise at 0° C. Thereaction mixture was stirred at R.T. for 1 h. The reaction was quenchedwith saturated aqueous NH₄Cl and concentrated to give a residue. Theresidue was purified on a silica gel column (DCM:MeOH=150:1) to givecrude 67-3 (2.9 g, 79.5%) as a yellow solid.

Preparation of (67a):

A solution of crude 67-3 (1.0 g, 0.98 mmol) in 80% HOAc (25 mL) wasstirred at 80-90° C. for 2 h. The crude product was purified on a silicagel column (eluted with DCM:MeO=20:1) to give 67a (133 mg, 32.5%) as awhite solid. ¹H NMR (DMSO, 400 MHz) δ 7.67 (d, J=7.2 Hz, 1H), 7.34 (d,J=12.8 Hz, 2H), 6.33-6.69 (m, 1H), 6.05 (d, J=6.8 Hz, 1H), 6.00-6.05 (m,1H), 5.76 (d, J=7.6 Hz, 1H), 5.45-5.61 (m, 1H), 4.60-4.63 (m, 1H),4.08-4.14 (m, 5H), 1.23-1.29 (m, 6H). ³¹P NMR (DMSO, 162 MHz) δ 1.93,1.30. ESI-MS: m/z 466.1 [M+Na]⁺.

Example 65 Preparation of Compound (68a)

To a solution of 67a (130 mg, 0.29 mmol) in MeOH (20 mL) was stirredunder H₂ (15 Psi) at R.T. for 2 h. The reaction mixture was filtered andconcentrated to give a residue. The residue was purified on a silica gelcolumn (eluted with DCM:MeO=20:1) to give a mixture of diastereomers of68a (90 mg, 69.2%) as a white solid. ¹H NMR (DMSO, 400 MHz) δ 7.61-7.68(m, 1H), 7.28-7.38 (m, 2H), 5.89-5.95 (m, 1H), 5.58-5.79 (m, 2H),5.18-5.39 (m, 2H), 4.53-4.85 (m, 1H), 4.04-4.39 (m, 4H), 3.71-3.83 (m,2H), 2.21-2.35 (m, 2H), 1.21-1.27 (m, 6H). ³¹P NMR (DMSO, 162 MHz) δ18.2, 18.02, 17.73, 17.56. ESI-MS: m/z 446.1 [M+H]⁺

Example 66 Preparation of Compound (69a)

Preparation of (69-1):

63-4 (3.0 g, 3.69 mmol) was co-evaporated twice with toluene. Theresulting bis-triflate was dissolved in anhydrous DMF (20 mL). Thesolution was cooled to 0° C. and treated with sodium hydride (60% inmineral oil; 177 mg, 0.43 mmol). The reaction was stirred at R.T. for 1h (TLC (PE:EA=2:1) showed complete disappearance of the bis-triflate andclean formation of the 2′,5′-anhydro intermediate). The reaction mixturewas used for the next step without any further workup

Preparation of (69-2):

To the above stirred reaction mixture was added NaSMe (9.0 g, 0.13 mmol)and 15-Crown-5 (4.87 g, 22.14 mmol) at 0° C. under nitrogen. Thesolution was stirred at R.T. for 2 h (TLC (PE:EA=1:1) showed thereaction was complete). The reaction was quenched with water. Themixture was extracted by EtOAc, washed with brine, and dried over MgSO₄.The mixture was filtered and concentrated to give a residue. The residuewas purified on a silica gel column (PE:EA=5:2) to give 69-2 (1.23 g,59.0%) as a white foam.

Preparation of (69-3):

To a stirred solution of 69-2 (1.34 g, 2.32 mmol) in anhydrous DCM (10mL) was added MMTrCl (1.32 g, 4.64 mmol), AgNO3 (1.17 g, 6.96 mmol) andCollidine (1.41 g, 11.6 mmol) at R.T. under nitrogen. The reactionmixture was stirred at R.T. for 1 h (TLC (PE:EA=1:1) showed the reactionwas complete). The mixture was filtered and concentrated. The residuewas purified on a silica gel column (PE:EA=8:1) to give 69-3 (1.31 g,66.5%) as a white foam.

Preparation of (69-4):

To a solution of 69-3 (900 mg, 1.06 mmol) in anhydrous MeCN (9 mL) wasadded DMAP (259 mg, 2.12 mmol), TEA (214 mg, 2.12 mmol) and TPSCl (640mg, 2.12 mmol) at R.T. under nitrogen. The reaction mixture was stirredat R.T. for 2 h (TLC (DCM:MeOH=10:1) showed the reaction was complete).NH₄OH (10 mL) was added, and the reaction mixture was stirred foranother 1 h (LCMS showed the reaction was complete). The solution wasdiluted with water, extracted with EtOAc. The organic layer was washedwith 1M HCl, saturated NaHCO₃ and brine, and dried over MgSO₄. Themixture was filtered and concentrated to give a residue. The residue waspurified on a silica gel column (DCM:MeOH=70:1) to give 69-4 (870 mg,68.5%) as a white solid.

Preparation of (69a):

69-4 (800 mg, 0.95 mmol) was dissolved in 80% HOAc aq. (50 mL). Thereaction mixture was heated to 75° C. overnight (LCMS showed thereaction was complete). The reaction mixture was concentrated andpurified on a silica gel column (DCM:MeOH=15:1) to give 69a (180 mg,62.5%) as a white solid. ¹H NMR (CD₃OD, 400 MHz) δ 8.05 (d, J=7.2 Hz,1H), 6.11 (dd, J=3.2 Hz J=15.6 Hz, 1H), 5.87 (d, J=7.6 Hz, 1H), 5.05(dt, J=4.8 Hz, J=53.6 Hz, 1H), 4.47 (dd, J=5.2 Hz J=17.6 Hz, 1H), 3.83(d, J=12.0 Hz, 2H), 2.84 (d, J=14.4 Hz, 2H), 2.15 (s, 3H). ESI-MS: m/z305.8 [M+H]⁺

Example 67 Preparation of Compound (70a)

To a solution of 63-5 (100 g, 182.5 mmol) in MeCN (2 L) was added 6N HClaq. (15 g). The mixture was stirred at 40° C. for 7 h, and thenneutralized to pH=5˜6 with a 25% ammonia solution (˜8 g). The mixturewas filtered to give a solid, which was further washed by PE to give anintermediate (32.2 g, 60%) as a white solid. To a mixture of theintermediate (32.2 g, 109.5 mmol), TEA (22.1 g, 219 mmol) and DMAP (1.34g, 11 mmol) in MeCN (1 L) was added with isobutyric anhydrous (69.2 g,438 mmol). The mixture was stirred at R.T. for 3 h. The reaction wasquenched by the addition of water (200 mL) and extracted with 2-Me-THF(800 mL). The organic layer was washed with saturated NaHCO₃ and brine.The organic layer was dried and concentrated to give a residue, whichwas purified by a silica gel column (10% toluene in heptane) to give 70a(42.3 g, 89%) as a white solid. ¹H NMR (CD₃OD, 400 MHz) δ 7.65 (d, J=8.0Hz, 1H), 5.95 (dd, J=2.8, 20.4 Hz, 1H), 5.55-5.74 (m, 3H), 4.33-4.41 (m,2H), 3.88 (s, 2H), 2.57-2.72 (m, 2H), 1.14-1.22 (m, 12H).

Example 68 Preparation of Compound (71a)

Preparation of (71-1):

To a solution of 63-4 (4.2 g, 5.17 mmol) in DMF (50 mL) at 0° C. wasadded NaH (227 mg of 60% dispersion, 5.7 mmol). The mixture was stirredat 0° C. for 2 h, and then LiBr (1.34 g, 15.5 mmol) was added. Themixture was stirred overnight at R.T., diluted with EA (150 mL) andwashed successively with water and brine. The organic layer was driedover Na₂SO₄ and concentrated. The residue was purified on a silica gelcolumn eluted with 10% EA in PE to give 71-1 as a yellow solid (2 g,66%)

Preparation of (71-2):

To a solution of 71-1 (1.74 g, 2.9 mmol) in THF (20 mL) at 0° C. wasadded 1N NaOH (3.2 mL, 3.2 mmol), and the mixture was stirred at 0° C.for 2 h. The mixture was partitioned between EA (100 mL) and water (20mL), and the organic layer was dried over Na₂SO₄ and evaporated todryness. The residue was purified on a silica gel column eluted with 20%EA in PE to give the 5′-OH derivative as a yellow solid (1.6 g, 90%).

To a solution of 5′-OH derivative (2.3 g, 3.76 mmol) in anhydrous DCM(20 mL) were added collidine (0.8 g, 6.7 mol) and MMTrCl (2.7 g, 8.7mmol). The reaction mixture was stirred at R.T. overnight. The mixturewas filtered and washed successively with saturated aqueous NaHCO₃ andbrine, dried over Na₂SO₄ and concentrated. The residue was purified on asilica gel column eluted with 10% EA in PE to give 71-2 as a yellowsolid (2.4 g, 73%).

Preparation of (71a):

To a solution of 71-2 (2.4 g, 2.72 mmol) in anhydrous CH₃CN (30 mL) wereadded TPSCl (1.65 g, 5.44 mmol), DMAP (0.663 g, 5.44 mmol) and NEt₃ (1.5mL) at R.T. The mixture was stirred at R.T. for 3 h, and 28% aqueousammonia (30 mL) was added. The mixture was stirred for 1 h. The mixturewas diluted with EA (150 mL) and washed successively with water,saturated aqueous NaHCO₃ and brine. The solvent was removed, and theresidue was purified on a silica gel column eluted with 2% MeOH in DCMto give a cytidine derivative as a yellow solid (1.5 g, 62%).

The cytidine derivative (1.35 g, 1.5 mmol) was dissolved in 80% AcOH (40mL), and the mixture was stirred at 60° C. for 2 h. The mixture wasconcentrated, and the residue was purified on a silica gel column using5% MeOH in DCM as elute to give 71a as a white solid (180 mg, 35%). ¹HNMR (MeOD, 400 MHz) δ 8.00 (d, J=7.2 Hz, 1H), 6.12 (dd, J=3.6 Hz, J=15.6Hz, 1H), 5.88 (d, J=7.6 Hz, 1H), 5.10 (dd, J=4.8 Hz, J=53.2 Hz, 1H),4.59 (dd, J=5.2 Hz, J=16.4 Hz, 1H), 3.95 (d, J=11.6 Hz, 1H), 3.76 (d,J=11.6 Hz, 1H), 3.70 (d, J=11.6 Hz, 1H), 3.63 (d, J=11.2 Hz, 1H);ESI-TOF-MS: m/z 337.9 [M+H]⁺.

Example 69 Preparation of Compound (72a)

Preparation of (72-1):

To a solution of 63-6 (1.0 g, 1.8 mmol) in 1,4-dioxane (2 mL) was addedTEA (3 mL) and 37% HCHO (3 mL). The reaction mixture was stirred for 10h at 60° C. The reaction was concentrated to dryness under vacuum, andthe residue was purified by column on a silica gel column(DCM:MeOH=100:1-30:1) to give 72-1 (470 mg, 45%) as a white foam. ¹H NMR(DMSO-d6, 400 MHz) δ 11.4 (s, 1H), 7.27-7.49 (m, 13H), 6.89 (d, J=8.8Hz, 2H), 4.90-4.95 (m, 1H), 4.58 (dd, J=5.2 Hz, J=23.6 Hz, 1H),3.96-4.07 (m, 4H), 3.73 (s, 3H), 3.50-3.62 (m, 1H), 3.37-3.39 (m, 1H),ESI-TOF-MS: m/z 596.9 [M+H]⁺.

Preparation of (72-2):

To a solution of 72-1 (430 mg, 0.72 mmol) in dioxane (2 mL) was added30% CH₃COOH (0.7 mL) and PtO₂ (290 mg). The reaction mixture was stirredunder H₂ (1 atm) at R.T. for 2 h. The mixture was filtered, and thefiltrate was concentrated to dryness. The residue was purified on asilica gel column (DCM:MeOH=100:1-30:1) to give 72-2 (268 mg, 64%) as awhite foam. ¹H NMR (DMSO-d6, 400 MHz) 811.3 (s, 1H), 7.27-7.46 (m, 13H),6.88 (d, J=8.8 Hz, 2H), 5.78 (d, J=20.8 Hz, 1H), 5.06-5.08 (t, J=20.8Hz, 1H), 4.49 (dd, J=4.2 Hz, J=24.4 Hz, 1H), 3.94-4.04 (m, 2H), 3.70 (s,3H), 3.59-3.63 (m, 1H), 3.52-3.53 (m, 1H), 3.34-3.40 (m, 1H), 1.66 (s,3H). ESI-TOF-MS: m/z 580.9 [M+H]⁺.

Preparation of (72-3):

To a solution of 72-2 (260 mg, 0.45 mmol) in anhydrous DCM (3 mL) wasadded AgNO₃ (228 mg, 1.35 mmol), collidine (223 mg, 1.8 mmol) and MMTrCl(456 mg, 1.35 mmol). The mixture was stirred at R.T. for 10 h. Thereaction mixture was filtered, and the filtrate was concentrated todryness. The residue was purified on a silica gel column(PE:EA=50:1-3:1) to give 72-3 (303 mg, 80%) as a white foam.

Preparation of (72-4):

To a solution of 72-3 (300 mg, 0.35 mmol) in anhydrous CH₃CN (3 mL) wasadded DMAP (107 mg, 0.88 mmol), TEA (141 mg, 1.4 mmol) and TPSCl (106mg, 0.35 mmol) at R.T. The reaction mixture was stirred at R.T. for 4 h.NH₄OH (1 mL) was added, and the mixture was stirred at R.T. for another1 h. The solvent was removed, and the residue was partitioned by EA andwater. The organic layer was washed by brine twice, dried andconcentrated to give a residue. The residue was purified on a silica gelcolumn (PE:EA=50:1-3:1) to give 72-4 (270 mg, 90%) as a white foam.

Preparation of (72a):

72-4 (260 mg, 0.31 mmol) in 10 mL of 60% HCOOH was stirred at R.T. for 2h. The solvent was removed, and the residue was washed with EA to give72a (31 mg, 32%) as a white powder. ¹H NMR (MeOD, 400 MHz) δ 7.85 (d,J=0.8 Hz, 1H), 6.12 (dd, J=4.0 Hz, J=15.2 Hz, 1H), 5.08-5.22 (m, 1H),4.58 (dd, J=4.8 Hz, J=14.8 Hz, 1H), 3.92 (d, J=15.6 Hz, 1H), 3.74-3.84(m, 3H), 1.94 (d, J=0.8 Hz, 1H). ESI-TOF-MS: m/z 307.9 [M+H]⁺.

Example 70 Preparation of Compound (73a)

Preparation of (73-1):

63-6 (600 mg, 1.06 mmol) in formic acid (5 mL, 80% in water) was stirredat R.T. overnight. Completion of the reaction was determined by TLC(DCM:MeOH=10:1). The solvent was removed to give crude 73-1 (290 mg,93.2%).

Preparation of (73-2):

To a solution of 73-1 (290 mg, 0.98 mmol) in pyridine (5 mL) andacetonitrile (5 mL) was added BzCl (371 mg, 2.65 mmol). The reactionmixture was stirred at 0° C. for 0.5 h. The reaction was warmed to R.T.and stirred for 2 h. Completion of the reaction was determined by LCMS.The reaction was quenched with water and extracted with EA. The organiclayer was washed with brine, dried over MgSO₄, filtered andconcentrated. The residue was purified on a silica gel column(DCM:MeOH=200:1) to give 73-2 (245 mg, 49.8%) as a white solid.

Preparation of (73-3):

To a solution of 73-2 (245 mg, 0.49 mmol) in anhydrous acetonitrile (2.5mL) was added TPSCl (394 mg, 0.98 mmol), DMAP (119.5 mg, 0.98 mmol) andTEA (98 mg, 0.98 mmol). The mixture was stirred at R.T. for 3 h.NH₂OH.HCl (68 mg, 0.98 mmol) and DBU (368 mg, 1.47 mmol) were added, andthe reaction mixture was stirred at R.T. for 2 h. The reaction mixturewas diluted with water and extracted with EtOAc. The combined organiclayer was washed with 1M HCl, saturated NaHCO₃ and brine, dried andconcentrated. The residue was purified on a silica gel column(DCM:MeOH=20:1) to give 73-3 (49 mg, 32.9%) as a white solid.

Preparation of (73a):

73-3 (49 mg, 0.1 mmol) in NH₃/MeOH (30 mL) was stirred at R.T. for 2days. The solvent was removed. The residue was purified on a silica gelcolumn (DCM:MeOH=30:1) to give 73a (12.9 mg, 44.0%) as a white solid. ¹HNMR (DMSO-d₆, 400 MHz) δ 10.07 (brs, 1H), 9.68 (brs, 1H), 7.02 (d, J=8.0Hz, 1H), 6.06 (dd, J=6.4 Hz, J=13.6 Hz, 1H), 5.94 (d, J=5.6 Hz, 1H),5.60 (d, J=8.4 Hz, 1H), 5.36 (t, J=5.2 Hz, 1H), 5.16 (dt, J=5.2 Hz,J=53.6 Hz, 1H), 4.31-4.35 (m, 1H), 3.58-3.76 (m, 2H), 3.57-3.58 (m, 2H).ESI-TOF-MS: m/z 308.1 [M−H]⁺.

Example 71 Preparation of Compound (74a)

Preparation of (74-1):

To a solution of 63-6 (1.2 g, 2.12 mmol) in anhydrous DCM (20 mL) wereadded collidine (750 mg, 6.51 mol) and MMTrCl (2.6 g, 8.5 mmol). Thereaction mixture was stirred at R.T. overnight. The reaction wasfiltered and washed successively with saturated aqueous NaHCO₃ andbrine, dried over Na₂SO₄ and concentrated. The residue was purified on asilica gel column eluted with 10% EA in PE to give 74-1 as a yellowsolid (1.4 g, 72%).

Preparation of (74-2):

To a stirred solution of 74-1 (600 mg, 0.715 mmol) in anhydrousacetonitrile (6 mL) were added TPSCl (432 mg, 1.43 mmol), DMAP (174 mg,1.43 mmol) and TEA (144 mg, 1.43 mmol). The mixture was stirred at R.T.for 2 h. Completion of the reaction was determined by TLC(DCM:MeOH=10:1). CH₃NH₂ (310 mg, 10 mmol) was added dropwise at 0° C.The reaction mixture was stirred at R.T. for 2 h. The mixture wasdiluted with water and extracted with EtOAc. The combined organic layerwas washed with 1M HCl, saturated NaHCO₃ and brine. The solvent wasremoved, and the residue was purified by prep-TLC (DCM:MeOH=10:1) togive 74-2 (307 mg, 50.45%) as a white solid.

Preparation of (74a):

74-2 (300 mg, 0.352 mmol) in formic acid (10 mL, 80% in water) wasstirred at R.T. overnight. Completion of the reaction was determined byTLC (DCM:MeOH=10:1). The solvent was removed to dryness. The residue wasdissolved in 20 mL of methanol. Ammonia (0.5 mL) was added, and themixture was stirred at R.T. for 5 mins. The solvent was removed, and theresidue was washed with PE (5×) to give 74a (103 mg, 95.3%) as a whitesolid. ¹H NMR (DMSO-d₆, 400 MHz) δ 7.79 (d, J=4.8 Hz, 1H), 7.72 (d,J=5.2 Hz, 1H), 6.10 (dd, J=4.4 Hz, J=14.8 Hz, 1H), 5.97 (brs, 1H), 5.73(d, J=7.6 Hz, 1H), 5.39 (brs, 1H), 5.08 (dt, J=4.2 Hz, J=53.2 Hz, 1H),4.37-4.40 (m, 1H), 3.73 (s, 2H), 3.54-3.70 (m, 2H), 2.73 (d, J=4.4 Hz,3H). ESI-TOF-MS: m/z 308.1 [M+H]⁺.

Example 72 Preparation of Compound (75a)

Preparation of (75-3):

To a stirred solution of 75-1 (20.0 g, 151 mmol) in anhydrous THF (200mL) was added NaH (7.8 g, 196 mmol) in portions at 0° C. The mixture wasstirred for 1 h, and 75-2 (65.0 g, 196 mmol) was added dropwise at 0° C.The mixture was stirred at R.T. for 10 h. The reaction was quenched withwater and extracted with EA. The reaction was washed with brine, and theorganic layer was concentrated to obtain crude 75-3 (72 g).

Preparation of (75-4):

Crude 75-3 (72 g, 151 mmol) was dissolved with 80% CH₃COOH (300 mL) andstirred for 10 h. The solvent was removed under reduced pressure. Theresidue was dissolved in EA and washed with saturated NaHCO₃ and brinesuccessively. The organic layer was dried over Na₂SO₄ and concentratedto dryness. The residue was purified on a silica gel column to give thecrude intermediate, which was dissolved in anhydrous pyridine (80 mL)and DCM (400 mL). A solution of DMTrCl (56.0 g, 166 mmol) in DCM (150mL) was added dropwise at 0° C. The mixture was stirred at R.T. for 10h. The reaction mixture was concentrated to dryness, and the residue waspurified by column on silica gel (PE:EA=2:1) to give 75-4 (58.5 g, 61%).

Preparation of (75-5):

To a stirred solution of 75-4 (10.0 g, 15.5 mmol) in anhydrous DMF (80mL) was added NaH (0.8 g, 20 mmol) at 0° C. The mixture was stirred atR.T. for 1 h, and BnBr (33.8 g, 20 mmol) was added. The reaction mixturewas stirred at R.T. for 10 h. The reaction was quenched with water andextracted with EA. The reaction was washed with brine, and the organiclayer was concentrated to give the crude intermediate (10.5 g, 92%) as awhite foam. The crude intermediate (10.2 g, 13.8 mmol) in 80% CH₃COOH(100 mL) was stirred at R.T. for 12 h. The solvent was removed. Theresidue was dissolved in EA, washed with saturated NaHCO₃ and brinesuccessively, dried and concentrated to give a residue. The residue waspurified on a silica gel column twice (PE:EA=3:1) to give 75-5 (4.2 g,70%) as a white foam.

Preparation of (75-6):

To a solution of 75-5 (4.0 g, 9.2 mmol) in anhydrous CH₃CN (30 mL) wasadded DIPEA (6.1 g, 47.6 mmol) and 2-cyanoethylN,N-diisopropylchlorophosphoramidite (2.8 g, 11.9 mmol). The mixture wasstirred at R.T. for 2 h. The solvent was removed, and residue waspartitioned by EA and saturated NaHCO₃. The organic layer was dried overMgSO₄ and concentrated to give a residue. The residue was purified on asilica gel column (PE:EA=3:1) to give 75-6 (5.1 g, 88%) as a whitesolid.

Preparation of (75-7):

To a solution of 75-6 (1.0 g, 1.6 mmol) and 63-9 (925 mg, 1.1 mmol) inanhydrous MeCN (1 mL) was added tetrazole (12 mL, 0.45M in MeCN, 5.5mmol) dropwise at R.T. After stirred for 3 h, TBDPH (0.96 mL, 5M 4.8mmol) was added. The reaction mixture was stirred at R.T. for 1 h. Themixture was diluted with EA and washed with saturated Na₂SO₃ and brine,dried over anhydrous Na₂SO₄ and concentrated. The residue was purifiedby silica gel chromatography (PE/EA=50:1 to 1:1) to give 75-7 (1.1 g,73.3%) as a white solid.

Preparation of (75a):

75-7 (1.0 g, 0.7 mmol) in 60% HCOOH (3 mL) was stirred at R.T. for 12 h.The solvent was removed. The residue was dissolved in EA and washed withsaturated NaHCO₃ and brine successively, dried and concentrated to givea residue. The residue was purified twice on a silica gel column(DCM:MeOH=30:1) to give crude 75a (510 mg, 86%) as a white foam. To asolution of crude 75a (275 mg, 0.33 mmol) in C₂H₅OH was added a fewdrops 1N NaOH until pH˜7.0. The mixture was stirred for 0.5 h. Themixture was concentrated to give a residue. The residue was purified byHPLC (MeCN and water, neutral system) to give 75a (sodium salt, 170 mg,64%) as a white solid. ¹H NMR (CD₃OD, 400 MHz) δ 8.01 (d, J=7.6 Hz, 1H),7.23-7.37 (m, 5H), 6.22 (dd, J=3.6 Hz, J=14.4 Hz, 1H), 6.01 (d, J=7.6Hz, 1H), 5.01-5.16 (m, 1H), 4.63-4.72 (m, 2H), 4.52-4.11 (m, 1H),4.23-4.29 (m, 1H), 3.91-4.09 (m, 3H), 3.69-3.81 (m, 3H), 3.51-3.60 (m,2H), 3.41-3.45 (m, 2H), 1.48-1.55 (m, 2H), 1.21-1.35 (m, 32H), 0.87-0.91(m, 3H). ³¹P NMR (CD₃OD, 162 MHz) δ −0.223. ESI-TOF-MS: m/z 788.3[M−H]⁺.

Example 73 Preparation of Compound (76a)

Preparation of (76-1):

To a solution of 73-1 (4.1 g, 13.95 mmol) in pyridine (40 mL) was addedAc₂O (3.13 g, 30.68 mmol) at R.T., and the mixture was stirredovernight. The mixture was concentrated, and the residue was purified ona silica gel column (PE:EA=3:1) to give 76-1 (4.0 g, 75.9%).

Preparation of (76-2):

To a solution of 76-1 (1.3 g, 3.44 mmol) in pyridine (20 mL) was addedNBS (1.22 g, 6.88 mmol) at R.T., and the mixture was stirred overnight.The mixture was concentrated, and the residue was purified on a silicagel column (PE:EA=4:1) to give 76-2 (1.43 g, 72.2%).

Preparation of (76-3):

To a solution of 76-2 (770 mg, 1.68 mmol) in dioxane (10 mL) was addedMe₆Sn₂ (1.1 g, 3.36 mmol) and (PPh₃)₂PdCl₂ (100 mg) under N₂ atmosphere.The mixture was heated at 80° C. for 4 h. The mixture was concentrated,and the residue was purified on a silica gel column to give anintermediate (400 mg, 43.96%). To a solution of the intermediate (330mg, 0.61 mmol) in anhydrous MeCN (3 mL) was added Selectflour® (462 mg,1.34 mmol) at R.T. The mixture was stirred at R.T. for 2 days. Themixture was concentrated, and the residue was purified on a silica gelcolumn (PE:EA=4:1) to give 76-3 (100 mg, 41.5%).

Preparation of (76a):

To a solution of 76-3 (100 mg, 0.25 mmol) in MeCN (2 mL) was added DMAP(62 mg, 0.51 mmol), TEA (51 mg, 0.51 mmol) and TPSCl (153 mg, 0.51mmol). The mixture was stirred at R.T. for 0.5 h. NH₃.H₂O (0.75 mL) wasadded. The mixture was stirred at R.T. for 0.5 h. The mixture wasextracted with EtOAc and washed with 1N HCl and brine. The organic layerwas dried and concentrated. The residue was purified on a silica gelcolumn (PE:EA=1:1) to give an intermediate (60 mg, 60.1%). Theintermediate (50 mg, 0.13 mmol) in NH₃/MeOH (5 mL) was stirred at R.T.for 3 h. The mixture was concentrated, and the residue was purified on asilica gel column (MeOH: DCM=1:10) to give 76a (30 mg, 76.2%). ¹H NMR(CD₃OD, 400 MHz) δ 8.25 (d, J=6.8 Hz, 1H), 6.09 (d, J=16.0 Hz, 1H), 5.00(dt, J=4.0 Hz, J=53.2 Hz, 1H), 4.48-4.54 (m, 1H), 3.73-3.95 (m, 4H).ESI-TOF-MS: m/z 312.1 [M+H]⁺.

Example 74 Preparation of Compound (77a)

77-1 (680 mg, 0.8 mmol) and triphenylphosphine (312 mg, 1.2 mmol) weredissolved in the mixture of 5 mL of dioxine and 0.25 mL of dry ethanol.A solution of diisopropyl azadicarboxylate (40% w solution in toluene,1.28 mmol) in 3 mL of dioxane was added, and the mixture was stirred atR.T. for 2 h. The mixture was evaporated to dryness. The residue wasdissolved in 10 mL of THF, cooled down to 4° C. and 2 equivalents ofTBAF in THF were added. The mixture was warmed up to R.T. and thesolvent was evaporated. The resulting nucleoside was treated with 80%HCOOH at R.T. for 3 h, and then the acid was evaporated. Isolated byisocratic silica gel chromatography using mixture of DCM (950 mL), MeOH(50 mL), and NH₄OH (2.5 mL) for elution gave 77a (80 mg, 30%). ¹H-NMR(DMSO-D₆) δ: 8.06 (s, 1H), 6.41 (s, 2H), 6.11-6.06 (dd, 1H), 5.98-5.89(dd, 1H), 5.65-5.64 (d, 1H), 5.34-5.26 (m, 2H), 5.18-5.11 (m, 1H),4.58-4.50 (dt, 1H), 4.42-4.36 (q, 2H), 3.50-3.28 (m, 2H), 1.30 (t, 3H).MS: 384 (M−1+HCOOH).

Example 75 Preparation of Compound (78a)

Preparation of (78-2):

To a solution of 78-1 (10.0 g, 37.17 mmol) in anhydrous pyridine (100mL) was added imidazole (9.54 g, 140.4 mmol) and TBSCl (21.1 g, 140.4mmol) at 25° C. The solution was stirred at 25° C. for 15 h. Thesolution was concentrated to dryness under reduced pressure. The residuewas dissolved in EtOAc (200 mL) and washed with water and brine. Theorganic layer was separated, dried over anhydrous Na₂SO₄ and filtered.The filtrate was concentrated in vacuo to give a residue. The residuewas purified by a silica gel column (PE/EA=10:1 to 2:1) to give anintermediate (11.8 g, 64%). To an ice-cold solution of the intermediate(11.8 g, 23.7 mmol) in CH₂Cl₂ (150 mL) was added a solution ofp-toluenesulfonic acid monohydrate (8.2 g, 47.5 mmol) in small portionunder N₂. The mixture was stirred at 25° C. for 30 min, and then washedwith saturated aq. NaHCO₃. The organic layer was separated, dried overanhydrous Na₂SO₄ and filtered. The filtrate was concentrated in vacuumto give a residue, which was purified by silica gel (PE/EA=10:1 to 1:1)to give 78-2 (6.7 g, 74%) as a solid.

Preparation of (78-3):

To a solution of 78-2 (6.7 g, 17.5 mmol) in anhydrous pyridine (50 mL)was added TMSCl (2.8 g, 26.2 mmol) in small portions at 0° C. under N₂.The reaction mixture was stirred at 25° C. overnight. AgNO₃ (77.8 g, 510mmol) and MMTrCl (156.8 g, 510 mmol) in anhydrous pyridine (50 mL) wasadded in small portions under N₂. The reaction mixture was stirred at25° C. overnight. Ammonia (30 mL) was added, and the reaction mixturewas stirred for 30 min. The mixture was filtered through a Buchnerfunnel, and the filtrate was washed with saturated NaHCO₃ solution andbrine. The organic layer was separated, dried over anhydrous Na₂SO₄,filtered and concentrated. Chromatography on silica gel (PE:EA=10:1 to2:1) gave an amine protected derivative (6.1 g, 53%). To a solution ofpyridine (142 mg, 1.8 mmol) in anhydrous DMSO (2 mL) at 0° C. was addedTFA (1.3 mg, 0.9 mmol) dropwise. The mixture was stirred at 25° C. untila clear solution formed. The solution was then added into a solution ofthe amine protected derivative (1.0 g, 1.5 mmol) and DCC (0.95 g, 4.6mmol) in anhydrous DMSO at 0° C. dropwise. Stirring was continued at 25°C. for 10 h. Water (10 mL) was added, and the mixture was stirred at 25°C. for 1 h. The precipitate was removed by filtration, and the filtratewas extracted with EtOAc (20 mL). The organic layer was washed withbrine (20 mL) and then dried over Na₂SO₄. The solvent was removed, andthe residue was purified on a silica gel column (EA:PE=10:1 to 2:1) togive the aldehyde derivative (850 mg, 85%). To a solution of thealdehyde derivative (2.6 g, 4.0 mmol) in 1,4-dioxane (30 mL) was added37% CH₂O (1.3 g, 16.0 mmol) and 2N NaOH aqueous solution (3.0 mL, 6.0mmol). The mixture was stirred at 25° C. for 2 h and then neutralizedwith AcOH to pH=7. To the reaction were added EtOH (10 mL) and NaBH₄(912 mg, 24.0 mmol). The reaction was stirred for 30 mins, and thenquenched with saturated aqueous NH₄Cl. The mixture was extracted withEA, and the organic layer was dried over Na₂SO₄. Purification by silicagel column chromatography (EA:PE=10:1 to 2:1) gave 78-3 (1.1 g, 40%) asa yellow solid.

Preparation of (78-4):

A stirred solution of 78-3 (685 mg, 1.0 mmol) in anhydrous CH₃CN (5 mL)and anhydrous pyridine (5 mL) was cooled to 0° C. BzCl (126 mg, 0.9mmol) was added, and the reaction mixture was stirred at 25° C. After1.5 h, water (5 mL) was added. The resulting mixture was extracted withDCM (2×30 mL). The combined extracts were washed with a saturatedaqueous solution of NaHCO₃ (20 mL), dried over MgSO₄, and evaporatedunder reduced pressure. The residue was purified by silica gel columnchromatography (DCM:MeOH=200:1 to 50:1) to give the Bz-protectedderivative (679 mg, 86%). To a stirred solution of Bz-protectedderivative (432 mg, 0.55 mmol) in anhydrous DMF (5 mL) was addedimidazole (258 mg, 3.85 mmol) and TBSCl (240.0 mg, 1.65 mmol). Themixture was stirred for 15 h. Water (10 mL) was added, and the mixturewas extracted with EA. The combined extracts were washed with aqueoussolution of NaHCO₃ (60 mL) and brine (60 mL), dried over MgSO₄, andevaporated under reduced pressure to give the two-TBS protectedderivative (680 mg, 137%). The two-TBS protected derivative (680 mg,0.75 mmol) was dissolved in anhydrous CH₃OH (5 mL), and NaOCH₃ (162 mg,3.0 mmol) was added. The reaction mixture was stirred at 35° C. for 2 h.The reaction was quenched with 80% AcOH (3 mL) and extracted with DCM(2×50 mL). The combined extracts were washed with aqueous solution ofNaHCO₃ (20 mL), dried over MgSO₄, and evaporated under reduced pressure.The residue was purified by silica gel column chromatography (EA:PE=20:1to 3:1) to give 78-4 (239 mg, 40%) as a white foam.

Preparation of (78-5):

78-4 (239 mg, 0.30 mmol) was co-evaporated with toluene three times toremove H₂O. To a solution of 78-4 in DCM (5 mL) was added DMAP (182 mg,1.50 mmol) and TfCl (69 mg, 0.45 mmol) at 0° C. under N₂. The mixturewas stirred 0° C. for 40 mins. Completion of the reaction was determinedby LCMS. The mixture was concentrated to give the crude Tf-derivative(353 mg). To a solution of the Tf-derivative in DMF (5 mL) was addedLiCl (31 mg, 0.76 mmol) at 0° C. under N₂. The mixture was stirred at25° C. for 40 mins. The mixture was washed with NaHCO₃ and extractedwith EA. The combined organic layer was dried over Na₂SO₄ andconcentrated to give crude 78-5 (268 mg) as a light yellow oil.

Preparation of (78a):

To a solution of 78-5 (268 mg, 0.328 mmol) in MeOH (5 mL) was added NH₄F(37 mg, 0.984 mmol) at 25° C. for 4 h. The solution was filtered andevaporated to dryness. The residue was dissolved in HCOOH (20 mL) andH₂O (4 mL) at 25° C. The mixture was stirred at 25° C. for 1 h andconcentrated. The mixture was dissolved in MeCN and purified byprep-HPLC to give 78a (32 mg) as a white solid. ¹H NMR (MeOD, 400 MHz) δ8.33 (s, 1H), 8.20 (s, 1H), 6.32 (dd, J=5.6, 12.4 Hz, 1H), 5.77 (m, 1H),4.69 (m, 1H), 3.85 (m, 1H). ESI-MS: m/z 317.9 [M+H]⁺.

Example 76 Preparation of Compound (79a)

Preparation of (79-1):

To a solution of 78-4 (1.1 g, 1.33 mmol) in anhydrous DCM (6.6 mL) at 0°C. under nitrogen was added Dess-Martin periodinane (1.45 g, 3.33 mol).The mixture was stirred at 25° C. for 4 h. The solvent was removed invacuum, and the residue triturated with methyl-t-butyl ether (30 mL).The mixture was filtered through a pad of MgSO₄, and the organic solventwas stirred with an equal volume of Na₂S₂O₃ in 30 mL of saturated NaHCO₃until the organic layer became clear (approx. 10 min). The organic layerwas separated, washed with brine, and dried over MgSO₄. Prior toremoving the solvent in vacuum, the residue was purified on a silica gelcolumn (PE:EA=7:1) to give 79-1 (750 mg, 75%) as a white solid.

Preparation of (79-2):

To a stirred solution of methyl-triphenyl-phosphonium bromide (1.74 g,4.89 mmol) in anhydrous THF (8 mL) was added n-BuLi (1.91 mL, 4.89 mmol,2.5 M in THF) at −78° C. dropwise. The mixture was stirred at 0° C. for1 h. 79-1 (750 mg, 0.81 mmol) was added, and the mixture stirred at 25°C. overnight. The reaction was quenched with saturated NH₄Cl (30 mL),and extracted with EtOAc (2×30 mL). The combined organic phase waswashed with brine, dried with MgSO₄, filtered and evaporated to drynessto give a light white solid. The solid was purified by columnchromatography (PE:EA=5:1) to give 79-2 (440 mg, 60%).

Preparation of (79-3):

To a solution of 79-2 (440 mg, 0.48 mmol) in MeOH (8 mL) was added Pd/C(500 mg, 10%) at R.T. under hydrogen atmosphere. The mixture was stirredat R.T. for 1.5 h. The mixture was filtered, and the filtrate wasconcentrated to dryness. Crude 79-3 (365 mg, 83%) was used for the nextstep without further purification.

Preparation of (79a):

79-3 (365 mg, 0.40 mmol) in MeOH (50 mL) was added NH₄F (5.6 g, 0.15mmol), and the solution was heated to refluxed overnight. Completion ofthe reaction was determined by LCMS. The mixture was filtered, and thefiltrate was concentrated to dryness. The residue was purified on asilica gel column (PE:EA=3:1) to give the amine protected derivative(173 mg, 77%) as a white solid. The amine protected derivative (100 mg,0.18 mmol) in formic acid (4.4 mL) was stirred at 25° C. overnight. Thesolution was concentration to dryness, and the residue was purified on asilica gel column (PE:EA=1:3) to give 79a (40 mg, 90%) as a white solid.¹H NMR (400 MHz, CD₃OD) δ 8.25 (s, 1H), 8.09 (s, 1H), 6.14 (dd, J=6.0,12.8 Hz, 1H), 5.58 (m, 1H), 4.45-4.48 (m, 1H), 3.60 (q, 2H), 1.66-1.74(m, 2H), 0.88 (t, 3H); ESI-MS: m/z 297.9 [M+H]⁺.

Example 77 Preparation of Compound (80a)

Preparation of (80-1):

To a solution of 78-3 (4.4 g, 6.4 mmol) in anhydrous pyridine (5 mL) andDCM (25 mL). A solution of DMTrCl (2.37 g, 7.04 mmol) in DCM (5 mL) wasadded dropwise at 0° C. under N₂. After 2 h, the reaction was quenchedwith CH₃OH and concentrated to dryness. The residue was purified on acolumn of silica gel (PE:EA=100:1 to 2:1) to obtain the DMTr protectedderivative (4.3 g, 68%). The DMTr protected derivative (2.2 g, 2.5 mmol)in 1M TBAF (2.5 mL) of THF (2.5 mL) solution was stirred at 25° C. for 3h. The solvent was removed in vacuum, and the residue was purified bycolumn chromatography (PE/EA=50:1 to 1:2) to give the diol derivative(1.86 g, 96%). To a solution of the diol derivative (1.3 g, 1.5 mmol) inanhydrous THF (5 mL) was added NaH (132 mg, 3.3 mmol) at 0° C. Themixture was stirred for 1 h, and TBI (276 mg, 0.75 mmol), and BnBr (558mg, 3.3 mmol) was added. The mixture was stirred for 10 h at 25° C. Thereaction was quenched with water, and the solvent was evaporated. Themixture was extracted with EA and brine. The organic layer was driedover Na₂SO₄, and evaporated to afford the crude product. The product waspurified by silica gel (PE/EA=100:1 to 3:1) to afford 80-1 (1.4 g, 90%)as a white foam.

Preparation of (80-2):

To a solution of 80-1 (1.3 g, 1.23 mmol) in anhydrous DCM (17 mL) wasadded Cl₂CHCOOH (1.57 g, 12.3 mmol) at −78° C. The mixture was stirredat −20-10° C. for 40 mins. The reaction was quenched with saturatedNaHCO₃, and diluted with DCM (50 mL). The mixture was washed with brine,and the organic solution was dried over Na₂SO₄ and concentrated invacuum. The residue was purified on a silica gel column (PE/EA=100:1 to1:1) to give 80-2 (652 mg, 70%) as a white foam.

Preparation of (80-3):

To a solution of 80-2 (630 mg, 0.84 mmol) in anhydrous DCM (5 mL) wasadded DAST (1.35 g, 8.4 mmol) at −78° C. The mixture was graduallywarmed to 0° C. The reaction was quenched with saturated NaHCO₃. Themixture was diluted with DCM (50 mL) and washed with brine. The organicsolution was dried over Na₂SO₄ and concentrated in vacuum. The residuewas purified on a silica gel column (PE/EA=100:1 to 2:1) to give 80-3 asa white solid (302 mg, 48%).

Preparation of (80a):

A mixture of 80-3 (210 mg, 0.28 mmol) and Pd(OH)₂ (200 mg) in methanol(3 mL) was stirred at 0° C. at 40 psi H₂ for 20 h. Pd(OH)₂ was filteredoff, and the filtrate was concentrated to dryness. The residue waspurified by column (DCM/MeOH=10:1) to give 80a (12 mg). ¹H NMR (400 MHz,CD₃OD) δ 8.33 (s, 1H), 8.20 (s, 1H), 6.33 (dd, J=6.0, 13.2 Hz, 1H), 5.79(t, J=5.6 Hz, 1H), 5.66 (t, J=5.2 Hz, 1H), 4.52-4.80 (m, 3H), 3.80-3.82(m, 2H). ESI-MS: m/z 302.0 [M+H]⁺.

Example 78 Preparation of Compound (81a)

Preparation of (81-2):

To a solution of 81-1 (20.0 g, 70.2 mmol) in anhydrous pyridine (200 mL)was added imidazole (19.1 g, 280 mmol) and TBSCl (42.1 g, 281 mmol) at25° C. The solution was stirred at 25° C. for 15 h, and thenconcentrated to dryness under reduced pressure. The residue wasdissolved in EtOAc and then filtered. The filtrate was concentrated todryness to give the TBS protected derivative (36.4 g, 99%). The TBSprotected derivative (36.5 g, 71.1 mmol) was dissolved in THF (150 mL).H₂O (100 mL), and then AcOH (300 mL) were added. The solution wasstirred at 80° C. for 13 h. The reaction was cooled to R.T., and thenconcentrated to dryness under reduced pressure to give 81-2 (31.2 g,61%) as a white solid.

Preparation of (81-3):

To a solution of 81-2 (31.2 g, 78.2 mmol) in anhydrous pyridine (300 mL)was added Ac₂O (11.9 g, 117.3 mmol). The mixture was stirred at 25° C.for 18 h. MMTrCl (72.3 g, 234.6 mmol) and AgNO₃ (39.9 g, 234.6 mmol)were added, and the solution was stirred at 25° C. for 15 h. H₂O wasadded to quench the reaction and the solution was concentrated todryness under reduced pressure. The residue was dissolved in EtOAc andwashed with water. The organic layer was dried over Na₂SO₄ and filtered.The filtrate was concentrated in vacuum to give a residue, which waspurified by silica gel (DCM:MeOH=200:1 to 50:1) to give the MMTrprotected amine derivative (35.2 g, 63%). The MMTr protected aminederivative (35.2 g, 49.3 mmol) was dissolved in NH₃/MeOH (300 mL). Themixture was stirred at 25° C. for 20 h. The solution was evaporated todryness, and purified by a silica gel column (DCM:MeOH=100:1 to 50:1) togive 81-3 as a yellow solid (28.6 g, 87%).

Preparation of (81-4):

To a solution of 81-3 (12.0 g, 17.9 mmol) in anhydrous DCM (200 mL) wasadded Dess-Martin periodinane (11.3 g, 26.8 mmol) at 0° C. The mixturewas stirred at 0° C. for 2 h, and then at R.T. for 2 h. The mixture wasquenched with a saturated NaHCO₃ and Na₂S₂O₃ solution. The organic layerwas washed with brine (2×) and dried over anhydrous Na₂SO₄. The solventwas evaporated to give the aldehyde (12.6 g), which was used directly inthe next step. To a solution of the aldehyde (12.6 g, 18.0 mmol) in1,4-dioxane (120 mL) was added 37% HCHO (11.6 g, 144 mmol) and 2N NaOHaqueous solution (13.5 mL, 27 mmol). The mixture was stirred at 25° C.overnight. EtOH (60 mL) and NaBH₄ (10.9 g, 288 mmol) were added, and thereaction was stirred for 30 mins. The mixture was quenched withsaturated aqueous NH₄Cl, and then extracted with EA. The organic layerwas dried over Na₂SO₄, and purified by silica gel column chromatography(DCM:MeOH=200:1 to 50:1) to give 81-4 (7.5 g, 59%) as a yellow solid.

Preparation of (81-5):

To a solution of 81-4 (3.8 g, 5.4 mmol) in DCM (40 mL) was addedpyridine (10 mL) and DMTrCl (1.8 g, 5.4 mmol) at 0° C. The solution wasstirred at 25° C. for 1 h. MeOH (15 mL) was added, and the solution wasconcentrated. The residue was purified by silica gel columnchromatography (DCM:MeOH=200:1 to 50:1) to give the MMTr protectedderivative (3.6 g, 66%) as a yellow solid. To a solution of the MMTrprotected derivative (3.6 g, 3.6 mmol) in anhydrous pyridine (30 mL) wasadded TBDPSCl (2.96 g, 10.8 mmol) and AgNO₃ (1.84 g, 10.8 mmol). Themixture was stirred at 25° C. for 15 h. The mixture was filtered andconcentrated. The mixture was dissolved in EtOAc and washed with brine.The organic layer was dried over Na₂SO₄., and then purified by silicagel column chromatography (DCM:MeOH=200:1 to 50:1) to give the TBDPSprotected derivative (3.8 g, 85.1%) as a solid. To a solution of theTBDPS protected derivative (3.6 g, 2.9 mmol) in anhydrous DCM (50 mL)was added Cl₂CHCOOH (1.8 mL) in anhydrous DCM (18 mL). The mixture wasstirred at −78° C. for 1 h. Cl₂CHCOOH (3.6 mL) was added at −78° C. Themixture was stirred at −10° C. for 30 mins. The mixture was quenchedwith saturated aqueous NaHCO₃ and extracted with DCM. The organic layerwas dried over Na₂SO₄, and then purified by silica gel columnchromatography (DCM:MeOH=200:1 to 50:1) to give 81-5 (2.2 g, 80%).

Preparation of (81-6):

To an ice cooled solution of 81-5 (800 mg, 0.85 mmol) in anhydrous DCM(20 mL) was added pyridine (336 mg, 4.25 mmol) and Tf₂O (360 mg, 1.28mmol) dropwise. The reaction mixture was stirred at 0° C. for 15 mins.The reaction was quenched by ice water and stirred for 30 mins. Themixture was extracted with EtOAc, washed with brine (50 mL) and driedover MgSO₄. The solvent was evaporated to give the crude bis(triflate)derivative. To the bis(triflate) derivative (790 mg, 0.73 mmol) inanhydrous DMF (35 mL) was added LiCl (302 mg, 7.19 mmol). The mixturewas heated to 40° C. and stirred overnight. Completion of the reactionwas determined by LCMS. The solution was washed with brine and extractedwith EtOAc. The combined organic layers were dried over MgSO₄, and theresidue was purified on a silica gel column (DCM/MeOH=100:1) to give81-6 (430 mg, 61%).

Preparation of (81a):

To 81-6 (470 mg, 0.49 mmol) in MeOH (85 mL) was added NH₄F (8.1 g, 5.92mmol), and the solution was heated to reflux overnight. The mixture wasfiltered, and the filtrate was concentrated to dryness. The residue waspurified on a silica gel column (DCM/MeOH=20:1) to give the diol (250mg, 84%) as a white solid. The diol (130 mg, 0.21 mmol) in formic acid(5 mL) was stirred at 25° C. overnight. The solution was concentrationto dryness, and the residue in MeOH (30 mL) was stirred at 70° C.overnight. Completion of the reaction was determined by LCMS and HPLC.The solvent was removed, and the crude product was washed with EtOAc togive 81a (58 mg, 81%) as a white solid. ¹H NMR (DMSO-d₆, 400 MHz) δ10.73 (br, 1H), 7.98 (s, 1H), 6.58 (br, 2H), 6.08 (q, J=4.8, 9.2 Hz,2H), 5.64 (dt, J=5.6, 52.8 Hz, 1H), 5.40 (m, 1H), 4.52 (m, 1H),3.80-3.82 (m, 2H), 3.64 (q, 2H). ESI-MS: m/z 333.8 [M+H]⁺, 666.6 [2M+H]⁺

Example 79 Preparation of Compound (82a)

Preparation of (82-1):

To a solution of 81-4 (310 mg, 0.33 mmol) in anhydrous DCM (10 mL) wasadded pyridine (130 mg, 1.65 mmol) and Tf₂O (139 mg, 0.49 mmol) dilutedby DCM dropwise at 0° C. The mixture was stirred at 0° C. for 15 mins.The reaction was quenched with ice cold water. The organic layer wasseparated and washed with brine. The organic layer was dried over Na₂SO₄and evaporated to give to give the triflate derivative (420 mg crude),which was used directly in the next step. To a solution of the triflatederivative (420 mg crude) in anhydrous pentan-2-one was added NaI (396mg, 2.64 mmol). The mixture was stirred at 40° C. for 3 h, and thendissolved with EtOAc. The organic layer were washed with Na₂S₂O₃ twiceand washed with brine. The organic layer was dried over Na₂SO₄ andevaporated to give a residue. The residue was purified by a column(DCM:MeOH=300:1 to 100:1) to give 82-1 (195 mg, 56% for two steps).

Preparation of (82-2):

To a solution of 82-1 (650 mg, 0.62 mmol) in MeOH (10 mL) was added NH₄F(45.8 g, 12.4 mmol). The mixture was refluxed overnight. The mixture wasfiltered and evaporated to dryness. The residue was purified on a silicagel column (DCM/MeOH=200:1 to 20:1) to give 82-2 (250 mg, 58%).

Preparation of (82-3):

To a stirred solution of 82-2 (300 mg, 0.43 mmol), Et₃N (217 mg, 2.15mmol) in anhydrous MeOH (10 mL) was added 10% Pd/C (50 mg). The mixturewas stirred in a hydrogenation apparatus (30 psi hydrogen) at R.T.overnight. The catalyst was filtrated off, and the filtrate wasevaporated to give a residue. The residue was purified on a silica gelcolumn (DCM/MeOH=200:1 to 20:1) to afford 82-3 as a white solid (180 mg,73%).

Preparation of (82a):

82-3 (110 mg, 0.19 mmol) was dissolved in HCOOH (18 g) and H₂O (6 g) at25° C., and stirred for 1 h. The solution was evaporated to dryness,dissolved in MeOH (30 mL). The mixture was stirred at 60° C. for 12 h.The solution was evaporated to dryness, and dissolved in EtOAc (50 mL).The mixture was stirred at 60° C. for 1 h. The mixture was filtered andwashed with EtOAc to give 82a as a white solid (45.3 mg, 80%). ¹H NMR(400 MHz, MeOD) 88.00 (s, 1H), 6.11-6.15 (m, 1H), 5.35-5.50 (m, 1H),4.53-4.59 (m, 1H), 3.54-3.64 (m, 2H), 1.26 (s, 3H). ESI-MS: m/z 299.76[M+1]⁺, 598.66 [2M+1]⁺.

Example 80 Preparation of Compound (83a)

Preparation of (83-1):

81-1 (5.7 g. 20 mmol) was co-evaporated with pyridine three times, andthen dissolved in pyridine (20 mL). The mixture was cooled to 0° C. andAc₂O (5.8 mL, 60 mmol) was added dropwise. The mixture was stirred at25° C. for 10 h, and then cooled to 0° C. AgNO₃ (8.5 g, 50 mmol), andthen MMTrCl (15.5 g, 50 mmol) were added in portions. The mixture wasstirred at 25° C. for 10 h. The reaction was quenched with saturatedNaHCO₃ and extracted with EA. The organic layer was dried over Na₂SO₄and concentrated. The residue was purified by silica gel columnchromatography (DCM/MeOH=100:1 to 50:1) to afford the Ac protectedderivative (12.1 g, 93%) as a light yellow solid. The Ac protectedderivative (12.1 g) was dissolved in methanolic NH₃ (saturated). Themixture was stirred at 25° C. for 14 h. The solvent was removed, and theresidue was purified on a silica gel column (DCM/MeOH=80:1 to 30:1) togive 83-1 (9.2 g, 87%).

Preparation of (83-2):

To a stirred solution of 83-1 (9.2 g, 16.5 mmol) in dry THF (300 mL) wasadded imidazole (9.0 g, 132 mmol) and PPh₃ (34.8 g, 132 mmol). Asolution of I₂ (26.0 g, 103 mmol) in THF (100 mL) was added dropwiseunder N₂ at 0° C. The mixture was stirred at 25° C. for 18 h and thenquenched with a Na₂S₂O₃ solution. The mixture was extracted with EtOAc.The organic layer was dried over Na₂SO₄ and concentrated. The residuewas purified on a silica gel column (DCM/MeOH=80:1 to 30:1) to give theiodide derivative (10.3 g, 93%) as a light yellow solid. To a stirredsolution of the iodide derivative (10.2 g, 15.3 mmol) in dry THF (300mL) was added DBU (4.7 g, 30.1 mmol). The mixture was stirred at 60° C.for 8 h. The solution was diluted with a NaHCO₃ solution and extractedwith EtOAc. The organic layer was dried over Na₂SO₄ and concentrated.The residue was purified on a silica gel column (PE/EtOAc=3:1 to 1:3) toafford 83-2 (6.2 g, yield 76%).

Preparation of (83-3):

To a stirred solution of 83-2 (5.42 g, 10 mmol) in anhydrous CH₃OH (100mL) was added PbCO₃ (13.7 g, 53.1 mmol). A solution of I₂ (12.3 g, 48.9mmol) in CH₃OH (300 mL) was added dropwise at 0° C. The mixture wasstirred at 25° C. for 10 h. The solution was quenched with a Na₂S₂O₃solution and extracted with DCM. The organic layer was washed with aNaHCO₃ solution, dried over Na₂SO₄ and concentrated to give a residue.The residue was purified by HPLC (0.1% HCOOH in water and MeCN) to givethe desired methoxyl derivative (2.4 g, 34%). To a stirred solution ofthe methoxyl derivative (2.4 g, 3.4 mmol) in dry pyridine (20 mL) wasadded BzCl (723 mg, 5.2 mmol) dropwise at 0° C. The mixture was stirredat 0° C. for 1 h. The solution was quenched with a NaHCO₃ solution andextracted with EtOAc. The organic layer was dried over Na₂SO₄ andconcentrated. Purified by a silica gel column (PE/EtOAc=5:1 to 1:1)afforded 83-3 (2.1 g, 77%) as a white solid.

Preparation of (83a):

83-3 (2.0 g, 2.5 mmol), BzONa (3.6 g, 25 mmol) and 15-crown-5 (5.5 g, 25mmol) were suspended in DMF (50 mL). The mixture was stirred at 110-125°C. for 5 days. The precipitate was removed by filtration, and thefiltrate was diluted with EA. The solution was washed with brine anddried over Na₂SO₄. The solvent was removed, and the residue was purifiedon a silica gel column (PE/EA=10/1 to 2/1) to afford the crude Bzprotected derivative (1.6 g, 80%). The Bz protected derivative (1.6 g,2.0 mmol) was dissolved in methanolic ammonia (100 mL), and the mixturewas stirred at 25° C. for 20 h. The solvent was removed, and the residuewas purified by a silica gel column (DCM/MeOH=100:1 to 20:1) to the diolderivative as a white solid (410 mg, 35%). The diol derivative (200 mg,0.34 mmol) was dissolved in HCOOH (24 g) and H₂O (6 g) at 25° C., andthe mixture was stirred at 25° C. for 1 h. The solution was evaporatedto dryness, and dissolved in MeOH (30 mL). The mixture was stirred at60° C. for 12 h. The solution was evaporated to dryness and dissolved inEtOAc (50 mL). The mixture was stirred at 60° C. for 1 h. The mixturewas then filtered and washed with EtOAc to give 83a as a white solid(46.1 mg, 43%). ¹H NMR (CD₃OD, 400 MHz) δ 7.92 (s, 1H), 6.22 (dd, J=1.6,18.8 Hz, 1H), 5.17-5.32 (m, 1H), 4.89-4.91 (m, 1H), 3.77 (m, 2H), 3.44(s, 3H). ESI-MS: m/z 316.1 [M+H]⁺.

Example 81 Preparation of Compound (84a)

Preparation of (84-2):

To a stirred solution of 84-1 (100.0 g, 265.9 mmol) in dry THF (1000 mL)was added Li(O-t-Bu)₃AlH (318.9 mL, 318.9 mmol) at −78° C. under N₂. Themixture was stirred at −78° C. for 1 h and then at R.T for 1 h. Thereaction mixture was cooled to −50° C. and quenched with ice and asaturated NH₄Cl solution. The mixture was extracted with EtOAc. Theorganic layer was dried over Na₂SO₄ and concentrated to afford the 1′-OHderivative (100.5 g) as a white solid. To a stirred solution of the1′-OH derivative (100.5 g, 265.9 mmol) in dry DCM (600 mL), NEt₃ (110mL) and MsCl (45.5 g, 298.0 mmol) were added dropwise at 0° C. Themixture was stirred at R.T. for 2 h. The mixture was quenched with icewater at 0° C. and extracted with DCM. The organic layer was dried overNa₂SO₄, concentrated and purified on a silica gel column (PE:EA=50:1 to5:1) to afford 84-2 (113.4 g, yield: 93.9%) as a white solid.

Preparation of (84-3):

To a suspension of compound 6-chloro-9H-purin-2-amine (70.1 g, 414.7mmol), HMDS (480 mL) and (NH₄)₂SO₄ (0.8 g) was added dry DCE (400 mL).The mixture was refluxed under N₂ for 18 h and then cooled to R.T. Tothe silylated 2-amino-6-chloropurine solution was added 84-2 (78.0 g,171.1 mmol) and TMSOTf (60 mL, 331.9 mmol). The mixture was refluxedovernight, concentrated and neutralized with a NaHCO₃ solution. Theresulting precipitate was filtered, and the filtrate was extracted withEtOAc. The organic layer was dried over Na₂SO₄ and concentrated.Chromatography on a silica gel column (PE:EA=5:1 to 2:1) gave 84-3 (10.8g, yield: 11.9%) as a light yellow solid.

Preparation of (84-4):

To a suspension of 84-3 (30.0 g, 56.6 mmol) in DCM (300 mL) were addedMMTrCl (34.9 g, 113.2 mmol) and AgNO₃ (19.3 g, 113.2 mmol). The reactionmixture was cooled to 0° C., and collidine (18.0 g, 150 mmol) was added.The resulting suspension was stirred at R.T. for 12 h. The suspensionwas filtered. The filtrate was extracted with DCM and washed with aNaHCO₃ solution. The organic layer was dried over Na₂SO₄ andconcentrated. Purification by a silica gel column (PE:EA=20:1 to 3:1) togive 84-4 (35.0 g, yield: 77.9%) as a light yellow solid. ¹H NMR (CDCl₃,400 MHz) δ 7.94-7.96 (m, 4H), 7.05-7.58 (m, 18H), 6.62-6.67 (m, 2H),6.55 (dd, J=6.0 Hz, J=9.6 Hz, 1H), 5.60-5.66 (m, 1H), 4.69-4.76 (m, 2H),4.55-4.58 (m, 1H), 3.64 (s, 1H). ESI-MS: m/z 802 [M+H]⁺.

Preparation of (84-5):

To a stirred solution of 84-4 (35.0 g, 43.6 mmol) in dry MeOH (400 mL)was added NaOMe (23.5 g, 436 mmol) and 2-mercapto-ethanol (30.6 g, 392.4mmol). The mixture was refluxed overnight. The pH was adjusted to 9-10with CO₂. The precipitate was filtered, and the filtrate wasconcentrated. Purification on a silica gel column (PE:EA=10:1 to 1:1)gave pure 84-5 (24.0 g, yield 95.7%) as a light yellow solid.

Preparation of (84-6):

To a solution of 84-5 (24.0 g, 41.7 mmol) in pyridine (250 mL) was addedDMTrCl (28.2 g, 83.5 mmol) at 0° C. The solution was stirred at R.T. for15 h. MeOH (50 mL) was added, and the mixture was concentrated todryness under reduced pressure. The residue was dissolved in EtOAc andwashed with water. The organic layer was dried over Na₂SO₄, filtered,concentrated and purified by a silica gel column (DCM:MeOH=200:1 to50:1) to give a first intermediate (27.6 g) as a yellow solid. To asolution of the first intermediate (27.6 g, 31.5 mmol) in DCM (200 mL)was added imidazole (4.3 g, 63 mmol) and TBSCl (9.5 g, 63 mmol). Themixture was stirred at R.T. for 12 h. The solution was washed withNaHCO₃ and brine. The organic layer was dried over Na₂SO₄, filtered,concentrated and purified by a silica gel column (DCM:MeOH=200:1 to100:1) to give a second intermediate (30.2 g) as a yellow solid. To asolution of the second intermediate (30.2 g, 30.4 mmol) in anhydrous DCM(50 mL) was added Cl₂CHCOOH (20 ml) in anhydrous DCM (500 mL). Themixture was stirred at −78° C. for 1 h. Cl₂CHCOOH (30 mL) was added at−78° C. The mixture was stirred at −20° C. for 2 h. The mixture wasquenched with saturated aqueous NaHCO₃ and extracted with DCM. Theorganic layer was dried over Na₂SO₄, and then purified by a silica gelcolumn (DCM:MeOH=200:1 to 30:1) to give 84-6 (18.0 g, 62.5%) as a whitesolid. ¹H NMR (400 MHz, MeOD) δ 8.27 (s, 1H), 7.16-7.38 (m, 12H),6.79-6.83 (m, 2H), 6.42 (dd, J=4.4 Hz, J=10.0 Hz, 1H), 4.54-4.62 (m,1H), 3.92 (d, J=8.8 Hz, 2H), 3.74 (s, 3H), 3.70-3.72 (m, 1H), 0.92 (s,9H), 0.11-0.13 (m, 6H). ESI-LCMS: m/z 690.0 [M+H]⁺.

Preparation of (84-7):

84-6 (7.0 g, 10.0 mmol) was added to a suspension of DMP (10.6 g, 25mmol) in anhydrous CH₂Cl₂ (100 mL) at 0° C. The mixture was stirred at25° C. for 2 h. The solvent was removed in vacuo, and the residuetriturated with diethyl ether (100 mL). The mixture was filtered througha pad of MgSO₄. The organic solvent was stirred with an equal volume ofNa₂S₂O₃.5H₂O in 100 mL of saturated NaHCO₃ until the organic layerbecame clear (10 min). The organic layer was separated, washed withbrine, and dried over MgSO₄. The solvent was removed in vacuo to give athird intermediate as a red solid (6.5 g, 95%). To a solution of thethird intermediate (6.5 g, 9.5 mmol) in 1,4-dioxane (80 mL) was added37% CH₂O (6.0 mL, 60 mmol) and 2N NaOH aqueous solution (9.5 mL, 19mmol). The mixture was stirred at 25° C. for 2 h and then neutralizedwith AcOH to pH 7. EtOH (30 mL) and NaBH₄ (3.8 g, 100 mmol) were added,and the mixture was stirred for 30 mins. The mixture was quenched withsaturated aqueous NH₄Cl, and then extracted with EA. The organic layerwas dried over Na₂SO₄. Purification by a silica gel column(DCM:MeOH=200:1 to 30:1) gave 84-7 (4.2 g, 58.3%) as a yellow solid.

Preparation of (84-8):

To a solution of 84-7 (4.2 g, 5.8 mmol) in DCM (50 mL) was addedpyridine (5 mL) and DMTrCl (1.9 g, 5.8 mmol) at −20° C. The solution wasstirred at 0° C. for 2 h. The reaction mixture was treated with MeOH (15mL), and then concentrated. The residue was purified by a silica gelcolumn (DCM:MeOH=200:1 to 50:1) to give the fourth intermediate (1.3 g)as a yellow solid. To a solution of the fourth intermediate (1.3 g, 1.3mmol) in anhydrous pyridine (15 mL) was added TBDPSCl (1.1 g, 3.9 mmol)and AgNO₃ (0.68 g, 4.0 mmol). The mixture was stirred at 25° C. for 15h. The mixture was filtered, concentrated, dissolved in EtOAc and washedwith brine. The organic layer was dried over Na₂SO₄. Purification by asilica gel column (DCM:MeOH=200:1 to 100:1) gave a fifth intermediate(1.4 g) as a solid. To a solution of the fifth intermediate (1.4 g, 1.1mmol) in anhydrous DCM (50 mL) was added Cl₂CHCOOH (0.7 ml) in anhydrousDCM (18 mL). The mixture was stirred at −78° C. for 1 h. Cl₂CHCOOH (1.5ml) was added at −78° C., and the mixture was stirred at −20° C. for 1.5h. The mixture was quenched with saturated aqueous NaHCO₃ and extractedwith DCM. The organic layer was dried over Na₂SO₄. Purification by asilica gel column (DCM:MeOH=200:1 to 50:1) gave 84-8 (650 mg, 11.6%) asa white solid.

Preparation of (84-9):

To a solution of pyridine (521 mg, 6.59 mmol) in anhydrous DMSO (5 mL)was added TFA (636 mg, 5.58 mmol) dropwise at 10° C. under N₂. Themixture was stirred until a clear solution formed. To this solution (0.8mL) was added a mixture of 84-8 (650 mg, 0.68 mmol) and DCC (410 mg, 2.0mmol) in anhydrous DMSO (5 mL) at R.T. under N₂. The mixture was stirredat 20° C. overnight. Water (30 mL) was added. The mixture was dilutedwith DCM (30 mL) and filtered. The filtrate was extracted with DCM. Theorganic layers were washed with saturated aqueous NaHCO₃, dried overNa₂SO₄ and concentrated in vacuo. The crude product was purified on asilica gel column (PE:EA=10:1 to 1:1) to give the sixth intermediate(600 mg) as a yellow solid. To a stirred solution ofMethyl-triphenyl-phosphonium bromide (714 mg, 2.0 mmol) in anhydrous THF(5 mL) was added n-BuLi (0.8 mL, 2.0 mmol, 2.5 M in THF) at −78° C.dropwise over 1 min. Stirring was continued at 0° C. for 1 h. The sixthintermediate (600 mg, 0.63 mmol) was added to the mixture, and themixture was stirred at 25° C. for 15 h. The reaction was quenched withsaturated NH₄Cl (20 mL) and extracted with EtOAc. The combined organicphase was dried with Na₂SO₄, filtered and evaporated to dryness to givea light yellow oil. The oil was purified by column chromatography(DCM:MeOH=200:1 to 50:1) to give 84-9 (250 mg, 38.5%) as a yellow solid.

Preparation of (84-10):

84-9 (250 mg, 0.26 mmol) was dissolved in THF (5.0 mL). TBAF (131 mg,0.5 mmol) was added at 20° C., and stiffing was continued for 2 h. Thesolution was evaporated to dryness. The residue was dissolved in EA (50mL) and washed with water (2×). The solution was evaporated to dryness,and purified by a silica gel column (PE:EA=10:1 to 1:2) to give 84-10(57.6 mg, 36.9%) as a white solid. ¹H NMR (400 MHz, MeOD) δ 8.34 (s,1H), 7.15-7.38 (m, 12H), 6.79-6.82 (m, 2H), 6.44 (dd, J=2.0 Hz, J=10.0Hz, 1H), 6.01 (dd, J=11.2 Hz, J=17.6 Hz, 1H), 5.51 (dd, J=1.6 Hz, J=17.2Hz, 1H), 5.35 (dd, J=1.6 Hz, J=17.2 Hz, 1H), 4.68-4.76 (m, 1H), 3.74 (s,3H), 3.63 (dd, J=2.0 Hz, J=12.8 Hz, 1H) 3.52 (dd, J=2.0 Hz, J=12.8 Hz,1H). ESI-LCMS: m/z 602.0 [M+H]⁺.

Preparation of (84a):

A solution of 84-10 (27 mg) in 1.5 mL of 80% formic acid stood at R.T.for 4.5 h and then concentrated to dryness. The residue was mixed withwater and lyophilized. MeOH (1.5 mL) and TEA (0.1 mL) were added, andthe mixture was concentrated. The precipitate from MeOH and EtOAc wasfiltered and washed with EtOAc to give 84 (9.3 mg) as a slightly-ambersolid. ¹H NMR (CD₃OD, 400 MHz) δ 8.44 (s, 1H), 6.57 (d, J=10.8 Hz, 1H),6.05 (dd, J=17.6 Hz, 10.8 Hz, 1H), 5.45 (dd, J=17.6 Hz, J=1.6 Hz, 1H),5.37 (dd, J=10.8 Hz, 1.6 Hz, 1H), 4.78 (dd, J=18.4 Hz, 17.2 Hz, 1H),3.67 (d, J=12.4 Hz, 1H), 3.56 (dd, J=12.4 Hz, 2.0 Hz, 1H); ESI-MS: m/z328.4 [M−H]⁻.

Example 82 Preparation of Compound (85a)

Preparation of (85-2):

A mixture of 85-1 (200 mg; 0.22 mmol) in pyridine (2.5 mL) andisobutyric anhydride (44 μL; 1.2 equiv) was stirred R.T. overnight. Themixture was concentrated, and the residue partitioned between EtOAc (50mL) and water. The organic layer was washed with 1N citric acid, water,saturated aqueous NaHCO₃ and brine. The mixture was dried with Na₂SO₄.The solvent was evaporated and the residue was purified on a silicacolumn (10 g column) using hexanes/EtOAc (30 to 100% gradient) to give85-2 (0.16 g, 75%).

Preparation of (85a):

A solution of 85-2 (0.16 g; 0.16 mmol) in 80% aq. HCOOH (5 mL) wasstirred at R.T. for 3 h. The solvent was evaporated and thenco-evaporated with toluene. Purification on a silica column (10 gcolumn) with CH₂Cl₂/MeOH (4-10% gradient) gave 85a (43 mg, 74%). ¹H-NMR(DMSO-d₆): δ 7.75 (d, 1H), 7.33 (d, 2H), 6.07 (dd, 1H), 5.75 (d, 1H),5.55 (dd, 1H), 5.43 (dt, 1H), 5.43 (t, 1H), 3.79 (dd, 2H), 3.63 (ddd,2H), 2.64 (sept, 1H), 1.12 (d, 6H). MS: m/z=362. [M+1]

Example 83 Preparation of Compound (86a)

Preparation of (86-2):

86-2 was prepared using a similar procedure for preparing 85-2 with thefollowing:

86-1 (220 mg; 0.22 mmol), (2.5 mL), isobutyric anhydride (0.13 mL; 3.6equiv), EtOAc (30 mL), and hexanes/EtOAc (30 to 100% gradient) to give86-2 (175 mg, 85%).

Preparation of (86a):

86a was prepared using a similar procedure for preparing 85a with thefollowing: 86-2 (117 mg; 0.13 mmol), 80% aq. HCOOH (4 mL) andCH₂Cl₂/MeOH (4-10% gradient) to give 86a (36 mg, 77%). ¹H-NMR (DMSO-d₆):δ 7.58 (d, 1H), 7.29 (d, 2H), 6.00 (s, 1H), 5.73 (d, 1H), 5.24 (ddd,1H), 4.55 (dd, 1H), 4.22 (dd, 2H), 3.80 (dd, 2H), 2.58 (sept, 1H), 1.08,1.07 (2d, 6H). MS: m/z=364 [M+1].

Example 84 Preparation of Compounds (87a)

Preparation of (87-2):

87-2 was prepared using a similar procedure for preparing 46-2 with thefollowing: 87-1 (178 mg, 0.3 mmol), hexanoic anhydride (0.14 mL, 2equiv.), pyridine (3 mL) to give 87-2. (120 mg, 50%).

Preparation of (87a):

87a was prepared using a similar procedure for preparing 85a with thefollowing: 87-2 (120 mg, 0.15 mmol), 80% aq. HCOOH and CH₂Cl₂/MeOH(4-10% gradient) to give 87a (62 mg, 85%). ¹H-NMR (CDCl₃): δ 8.2 (br,1H), 7.42 (d, 1H), 6.8 (br, 1H), 6.03 (d, 1H), 5.77 (dd, 1H), 5.64 (dd,1H), 5.51 (ddd, 1H), 4.43 (dd, 2H), 3.82 (dd, 2H), 2.41 (m, 2H), 2.33(m, 2H), 1.64 (m, 4H), 1.31 (m, 8H), 0.82 (m, 6H). MS: m/z=488 [M−1].

Example 85 Preparation of Compound (88a)

Preparation of (88-2):

88-2 was prepared using a similar procedure for preparing 85-2 with thefollowing: 85-1 (220 mg; 0.24 mmol), pyridine (3 mL),dodecanoycanhydride (0.12 g; 1.3 equiv), EtOAc (50 mL) and hexanes/EtOAc(25 to 80% gradient) to give 88-2 (0.22 g, 85%).

Preparation of (88a):

88a was prepared using a similar procedure for preparing 85a with thefollowing: 88-2 (0.19 g; 0.17 mmol), 80% aq. HCOOH (5 mL) andCH₂Cl₂/MeOH (4-10% gradient) to give 88a (66 mg, 82%). ¹H-NMR (DMSO-d₆):δ 7.77 (d, 1H), 7.35 (d, 2H), 6.07 (dd, 1H), 5.77 (d, 1H), 5.60 (dd,1H), 5.55 (ddd, 1H), 5.43 (t, 1H), 3.78 (dd, 2H), 3.65 (ddd, 2H), 2.41(m, 2H), 1.56 (m, 2H), 1.24 (m, 16H), 0.85 (m, 3H). MS: m/z=474 [M−1].

Example 86 Preparation of Compounds (89a) and (90a)

Preparation of (89-2):

To a solution of 89-1 (175 mg; 0.18 mmol) in MeCN (2.5 mL) at 0° C. wasadded TMSBr (0.28 mL; 10 equiv.). The mixture was stirred at R.T. for 1h, evaporated and treated with water. The obtained white solid wasfiltered, dried and washed with CH₂Cl₂. The white solid was thendissolved in NMP (2 mL) and treated with DIPEA (94 μL; 3 equiv.) andpivaloyloxymethyliodide (84 μL; 3 equiv.). The mixture was stirred atR.T. for 1 day, and then partitioned between water (20 mL) andtert-butyl methyl ether (TBME; 60 mL). The organic layer was washed withsaturated aqueous NaHCO₃, water and brine. The combined aqueous washingswere back extracted with TBME (2×20 mL). The combined organic extractwas dried and purified on a silica column (10 g column) withCH₂Cl₂/i-PrOH (2-10% gradient) to give 89-2 (42 mg, 26%).

Preparation of (89a):

A solution of 89-2 in 80% aq. HCOOH was stirred at R.T. for 3 h. Thesolvent was evaporated and then co-evaporated with toluene. Purificationon a silica column (10 g column) with CH₂Cl₂/MeOH (4-15% gradient) gave89a (17 mg, 74%). ¹H-NMR (CD₃OD): δ 7.47 (d, 1H), 6.28 (dd, 1H), 6.04(dd, 1H), 5.77-5.71 (m, 2H), 5.53 (m, 4H), 5.18 (ddd, 1H), 5.60 (dd,1H), 3.77 (dd, 2H), 1.08 (m, 18H). ³¹P-NMR (CD₃OD): δ 17.64. MS: m/z=598[M+1].

Preparation of (90a):

A mixture of 89a (12 mg; 0.02 mmol) in EtOH (1 mL) and Pd/C (10%; 2.5mg) was stirred overnight under an atmospheric pressure of hydrogen. Themixture was filtered through a Celite pad. The solvent was evaporatedand the product was purified on a silica column (10 g column) withCH₂Cl₂/MeOH (4-17% gradient) to give 90a (6 mg, 50%). ¹H-NMR (CD₃OD): δ7.51 (d, 1H), 5.79 (d, 1H), 5.65-5.54 (m, 5H), 5.20 (ddd, 1H), 5.60 (dd,1H), 3.70 (dd, 2H), 2.17-2.06 (m, 1H), 2.02-1.87 (m, 3H), 1.13 (m, 18H).³¹P-NMR (CD₃OD): δ 33.16. MS: m/z=600 [M+1].

Example 87 Preparation of Compound (91a)

Preparation of (91-2):

To a solution of triethylammoniumbis(isopropyloxycarbonyloxymethyl)phosphate (0.33 mmol, prepared from110 mg of bis(POC)phosphate and 0.1 mL of Et₃N) in THF (2 mL) was added86-1 (100 mg; 0.11 mmol), followed by diisopropylethyl amine (0.19 mL;10 equiv), BOP-Cl (140 mg; 5 equiv) and 3-nitro-1,2,4-triazole (63 mg; 5equiv). The mixture was stirred at R.T. for 90 mins., and then dilutedwith CH₂Cl₂ (30 mL). The mixture was washed with saturated aqueousNaHCO₃ and brine. The mixture was dried with Na₂SO₄. The solvent wasevaporated, and the residue was purified on a silica column (10 gcolumn) with hexanes/EtOAc (40-100% gradient) to give 91-2 (117 mg,90%).

Preparation of (91a):

91a was prepared using a similar procedure for preparing 85a with thefollowing: 91-2 (87 mg; 0.07 mmol), 80% aq. HCOOH (5 mL) and CH₂Cl₂/MeOH(4-15% gradient) to give 91a (36 mg, 85%). ¹H-NMR (CD₃CN): δ 7.67 (dd,1H), 6.35 (dd, 1H), 6.1 (br, 2H), 5.82 (d, 1H), 5.62 (m, 4H), 5.22 (dm,1H), 4.98 (br, 1H), 4.89 (m, 2H), 4.49 (d, 1H), 4.34 (m, 2H), 3.88 (dd,2H), 1.29 (d, 6H), 1.28 (d, 6H); ³¹P-NMR (CD₃CN): δ −4.49. MS: m/z=606[M+1].

Example 88 Preparation of Compound (92a)

Preparation of (92-2) and (92-3):

To a solution of triethylammonium bis(POM)phosphate (0.48 mmol, preparedfrom 176 mg of bis(POM)phosphate and 0.15 mL of Et₃N) in THF (2 mL) wasadded 92-1 (150 mg; 0.18 mmol) followed by diisopropylethyl amine (0.31mL; 10 equiv), BOP-Cl (229 mg; 5 equiv), and 3-nitro-1,2,4-triazole (103mg; 5 equiv). The mixture was stirred at R.T. for 90 mins., and thendiluted with CH₂Cl₂ (30 mL). The mixture was washed with saturatedaqueous NaHCO₃ and brine. The mixture was dried with Na₂SO₄. The solventwas evaporated, and the residue was purified on a silica column (10 gcolumn) with CH₂Cl₂/i-PrOH (2-10% gradient) to obtain 92-2 (44 mg, 21%)and 92-3 (73 mg, 28%).

Preparation of (92a):

A mixture of 92-2 and 92-3 (73 mg and 44 mg) and 80% aq. HCOOH (3 mL)was heated for 30 mins., at 35° C. The solvent was evaporated and thencoevaporated with toluene. The solvent was evaporated, and the residuewas purified on a silica column (10 g column) with CH₂Cl₂/MeOH (4-10%gradient) to obtain 92a (40 mg, 75%). ¹H-NMR (DMSO-D₆): δ 10.6 (br, 1H),7.76 (s, 1H), 6.44 (br, 2H), 5.99 (dd, 1H), 5.83 (d, 1H), 5.53-5.27 (2m, 6H), 4.39 (dt, 1H), 4.04 (m, 2H), 1.17 (s, 3H), 1.06, 1.08 (2 s,18H). ³¹P-NMR (DMSO-d₆): δ −4.09. MS: m/z=608 [M+1].

Example 89 Preparation of Compound (93a)

Preparation of (93-2) and (93-3):

93-2 and 93-3 (68 mg and 80 mg, respectively) were prepared in the samemanner from 93-1 (200 mg; 0.23 mmol) and bis(POM) phosphate (230 mg)with DIPEA (0.4 mL), BopCl (290 mg), and 3-nitro-1,2,4-triazole (130 mg)in THF (3 mL) as 92-2 and 92-3 from 92-1.

Preparation of (93a):

93-2 and 93-3 (68 mg and 80 mg, respectively) were converted into 93 (42mg) with formic acid in the same manner as 92 from 92-2 and 92-3. ¹H-NMR(DMSO-D₆): δ 7.73 (s, 1H), 6.46 (br, 2H), 6.04 (dd, 1H), 5.91 (dd, 1H),5.87 (d, 1H), 5.48 (d, 4H), 5.33 (m, 1H), 5.24 (ddd, 1H), 4.60 (dt, 1H),4.07 (m, 2H), 1.07, 1.06, 1.05 (4 s, 18H). ³¹P-NMR (DMSO-d₆): δ −4.37.MS: m/z=620 [M+1].

Example 90 Preparation of Compound (94a)

To a solution of 93a (53 mg; 0.09 mmol) in EtOH (2 mL) was added 10%Pd/C (10 mg). The mixture stirred under hydrogen at atmospheric pressurefor 1 h. The mixture was filtered through a Celite pad, and the filtrateevaporated. Purification on a silica column (10 g column) withCH₂Cl₂/MeOH (4-11% gradient) yielded 94a (45 mg, 81%). ¹H-NMR (DMSO-D₆):δ 10.6 (br, 1H), 7.81 (s, 1H), 6.4 (br, 2H), 5.97 (dd, 1H), 5.85 (d,1H), 5.60-5.44 (m, 5H), 4.37 (m, 1H), 4.11 (ddd, 2H), 1.66 (m, 2H),1.09, 1.06 (2 s, 18H), 0.81 (7, 3 H); ³¹P-NMR (DMSO-d₆): δ −4.10. MS:m/z=622 [M+1].

Example 91 Preparation of Compounds (95a) and (96a)

Preparation of (95-1):

To a solution of 5-Amino-2H-[1,2,4]triazin-3-one (180 mg, 1.5 mmol) inHMDS was added a catalytic amount of (NH₄)₄SO₄. The mixture was heatedto reflux for 5 h. HMDS was evaporated to give a crude product. To asolution of the crude product in anhydrous CH₃CN was added 70a (220 mg,0.5 mmol) and TMSOTf (0.45 mL, 2.5 mmol). The mixture was heated toreflux for 24 h in a sealed tube. The reaction was quenched with NaHCO₃and diluted with EA. The organic solvent was removed, and the residuewas purified by prep-TLC first, and the by RP-HPLC (0.5% HCOOH in waterand MeCN) to give the pure 95-1 (100 mg, 46%).

Preparation of (95-2):

To a solution of 95-1 (80 mg, 0.18 mmol) in anhydrous CH₃CN was added1,2,4-triazole (911 mg, 11.7 mmol) and TEA (1.45 g, 14.4 mmol). Themixture was cooled to 0° C. and POCl₃ was added. The reaction mixturewas stirred at 25° C. for 24 h. The solvent was evaporated andpartitioned with EA and water. The organic layer was concentrated togive the crude 95-2 (80 mg, 90%).

Preparation of (95a):

95-2 (90 mg, 0.18 mmol) was dissolved in 20 mL of saturated THF ammonia.The resulting solution was stirred at 25° C. for 2 h. The solvent wasremoved, and the residue was purified on a silica gel column (EA:PE=6:1)to give 95a as a white solid (70 mg, 70%).

Preparation of (96a):

95a (70 mg, 0.16 mmol) was dissolved in 20 mL of saturated MeOH ammonia.The resulting solution was stirred at 25° C. for 2 h. The solvent wasremoved, and the residue was purified by RP-HPLC (0.5% HCOOH in waterand MeCN) to give 96a (5 mg, 11%) as a white solid. ¹H NMR (CD₃OD, 400MHz) δ 7.57 (s, 1H), 6.35 (dd, J=3.6 Hz, J=15.6 Hz, 1H), 5.45-5.47 (m,1H), 4.70 (dd, J=4.8 Hz, J=16.2 Hz, 1H), 3.83 (s, 2H), 3.71 (d, J=1.6Hz, 2H). ESI-TOF-MS: m/z 295.1 [M+H]⁺.

Example 92 Preparation of Compounds (97a-g)

Dry nucleoside (0.05 mmol) was dissolved in a mixture of DMF (3 mL) andDMA-DMF (0.04 mL, 0.1 mmol). The reaction was kept at ambienttemperature for 4 h and then evaporated to dryness. The residue wasdissolved in a mixture of PO(OMe)₃ (0.7 mL) and pyridine (0.3 mL). Themixture was evaporated in vacuum for 15 min. at 42° C., than cooled downto R.T. N-Methylimidazole (0.009 mL, 0.11 mmol) was added followed byPOCl₃ (9 μl, 0.11 mmol). The mixture was kept at R.T. for 20-40 mins.The reaction was controlled by LCMS and monitored by the appearance ofthe corresponding nucleoside 5′-monophosphate. After completion of thereaction, tetrabutylammonium salt of pyrophosphate (150 mg) was added,followed by DMF (0.5 mL) to get a homogeneous solution. After 1.5 h atambient temperature, the reaction was diluted with water (10 mL). Themixture was loaded on the column HiLoad 16/10 with Q Sepharose HighPerformance, and separation was done in a linear gradient of NaCl from 0to 1N in 50 mM TRIS-buffer (pH7.5). The triphosphate (97a-f) was elutedat 75-80% B. The corresponding fractions were concentrated. The residuewas dissolved in 5% ammonium hydroxide, kept for 15 min. at R.T. andconcentrated. Desalting was achieved by RP HPLC on Synergy 4 micronHydro-RP column (Phenominex). A linear gradient of methanol from 0 to30% in 50 mM triethylammonium acetate buffer (pH 7.5) was used forelution. The corresponding fractions were combined, concentrated andlyophilized 3 times to remove excess of buffer.

TABLE 4 Triphosphates obtained from Example 92 Structure MS (M − 1) P(α)P(β) P(γ)

528.0 −6.71  −6.82  (d) −21.43 (t) −11.35 −11.47 (d)

544.0 −6.25  (bs) −21.45 (bs) −11.44 −11.56 (d)

575.7 −8.86  −9.00  (d) −22.95 (t) −11.81 −11.94 (d)

545.9 −9.41  −9.44  (d) −23.04 (t) −12.00 −12.13 (d)

552.1 −10.32 −10.44 (d) −23.26 (t) −11.84 −11.96 (d)

508.4 −8.30  (bs) −22.72 (bs) −11.51 −11.63 (d)

550.1 −9.17  −9.29  (d) −23.04 (t) −11.97 −12.09 (d)

Example 93 Preparation of Compounds (98a-e) and (99a)

Dry nucleoside (0.05 mmol) was dissolved in a mixture of PO(OMe)₃ (0.7mL) and pyridine (0.3 mL). The mixture was evaporated in vacuum for 15mins. at 42° C., than cooled down to R.T. N-Methylimidazole (0.009 mL,0.11 mmol) was added followed by POCl₃ (94 μl, 0.11 mmol). The mixturewas kept at R.T. for 20-40 mins. The reaction was controlled by LCMS andmonitored by the appearance of the corresponding nucleoside5′-monophosphate. After completion of the reaction, tetrabutylammoniumsalt of pyrophosphate (150 mg) was added, followed by DMF (0.5 mL) toget a homogeneous solution. After 1.5 h at ambient temperature, thereaction was diluted with water (10 mL) and loaded on the column HiLoad16/10 with Q Sepharose High Performance. Separation was done in a lineargradient of NaCl from 0 to 1N in 50 mM TRIS-buffer (pH7.5). Thetriphosphate (98a-e) was eluted at 75-80% B. The corresponding fractionswere concentrated. Desalting was achieved by RP HPLC on Synergy 4 micronHydro-RP column (Phenominex). A linear gradient of methanol from 0 to30% in 50 mM triethylammonium acetate buffer (pH 7.5) was used forelution. The corresponding fractions were combined, concentrated andlyophilized 3 times to remove excess of buffer.

TABLE 5 Compounds obtained from Example 93 Structure MS (M − 1) P(α)P(β) P(γ)

538.0 −5.21  −5.33  (d) −20.56 (t) −11.09 −11.20 (t)

556.2 −10.85 (bs) −23.11 (bs) −11.76 −11.88 (d)

540.4 −8.86  (bs) −23.84 (t) −11.68 −11.80 (d)

536.0 −9.35  −9.47  (d) −23.05 (t) −11.60 −11.72 (d)

545.9 −10.54 −10.66 −23.26 −11.80 −11.93 (d)

357.2 1.42 (s) NA NA

Example 94 Preparation of Compound (100a)

Preparation of (100-2):

To an ice-cold solution of 100-1 (22 mg; 0.055 mmol) in acetonitrile(0.5 mL) was added TMSBr (80 μL; 10 equiv.). The resulting mixture wasstirred at R.T. for 1 h. The mixture was concentrated, and the residuewas partitioned between water and diethyl ether. The aqueous layer waswashed with Et₂O, neutralized with triethylammonium bicarbonate bufferand lyophilized to yield the triethylammonium salt of 100-2.

Preparation of (100a):

100-2 was rendered anhydrous by coevaporating with pyridine and toluene.Anhydrous 100-2 was dissolved in HMPA (1 mL) and 1,1-carbonyldiimidazole(32 mg; 0.2 mmol) was added. The mixture was stirred at R.T. for 6 h. Asolution of tetrabutylammonium pyrophosphate (0.22 g; ˜0.2 mmol) in DMF(2 mL) was added. The mixture was stirred overnight at R.T. The mixturewas diluted with triethylammonium acetate buffer and purified by RP-HPLCwith a gradient 0-60% B (A: 50 mM aqueous TEAA, B: 50 mM TEAA in MeOH)and repurified by RP-HPLC with a gradient 0-30% B to give 100a. ³¹P-NMR(D₂O): δ 3.22 (d, 1P), −8.21 (br, 1P), −22.91 (br, 1P). MS: m/z=528(M−1).

Example 95 Preparation of Compound (100b)

Preparation of (100-4):

100-4 was prepared from 100-3 (54 mg; 0.13 mmol) in acetonitrile (1.3mL) with TMSBr (0.18 mL) using a similar procedure as described for thepreparation of 100-2.

Preparation of (100b):

100b was prepared from 100-4 in HMPA (2 mL) with CDI (84 mg) andtetrabutylammonium pyrophosphate (0.5 g) in DMF (2 mL) using a similarprocedure as described for the preparation of 100a. ³¹P-NMR (D₂O): δ17.90 (d, 1P), −9.00 (d, 1P), −22.91 (t, 1P). MS: m/z=530 (M−1).

Example 96 Preparation of Compound (100c)

Preparation of (100-6):

100-6 was prepared from 100-5 (40 mg; 0.09 mmol) in acetonitrile (1 mL)with TMSBr (0.1 mL) using a similar procedure as described for thepreparation of 100-2.

Preparation of (100c):

100c was prepared from 100-6 in HMPA (1.5 mL) with CDI (50 mg) andtetrabutylammonium pyrophosphate (0.3 g) using a similar procedure asdescribed for the preparation of 100a. ³¹P-NMR (D₂O): δ −7.13 (br, 1P),−10.14 (d, 1P), −22.84 (br, 1P). ¹⁹F-NMR (D₂O): δ −117.53 (dd, 1F),−197.8 (m, 1F). MS: m/z=545.5 (M−1).

Example 97 Preparation of Compounds (100d) and (100e)

Preparation of (100-8):

To an ice-cold solution of diastereomers 100-7 (35 mg; 0.08 mmol) inacetonitrile (1 mL) was added TMSBr (0.1 mL; 10 equiv.). The resultingmixture was stirred overnight at R.T. and then concentrated. The residuewas partitioned between water and CH₂Cl₂. The aqueous layer was washedwith CH₂Cl₂, neutralized with triethylammonium bicarbonate buffer andlyophilized to yield the triethylammonium salt of 100-8.

Preparation of (100d) and (100e):

100-8 was rendered anhydrous by coevaporating with pyridine and toluene.Anhydrous 100-8 was dissolved in DMF (1.5 mL) and CDI (54 mg; 0.3 mmol)was added. The mixture was stirred at R.T. for 7 h. A solution oftetrabutylammonium pyrophosphate (0.3 g; ˜0.3 mmol) in DMF (4 mL) wasadded. The mixture was stirred at R.T for 3 days. The mixture wasdiluted with triethylammonium acetate buffer. Two consecutive RP-HPLCpurifications with a gradient 0-60% B (A: 50 mM aqueous TEAA, B: 50 mMTEAA in MeOH) and 0-40% B gave 100d and 100e as single diastereomers.100d: ³¹P-NMR (D₂O): δ 4.28 (dd, 1P), −6.37 (d, 1P), −22.36 (t, 1P). MS:m/z=548.1 (M−1). 100e: ³¹P-NMR (D₂O): δ 4.13 (dd, 1P), −6.38 (d, 1P),−22.46 (t, 1P). MS: m/z=548.1 (M−1).

Example 98 Preparation of Compound (101a)

Preparation of (101-1):

To a solution of 59-4 (1.5 g, 2.39 mmol) in anhydrous DCM (100 mL) wasadded Dess-Martin periodinane (5.2 g, 11.95 mmol) at 0° C. undernitrogen. The mixture was stirred at R.T. for 5 h. The mixture waspoured into NaHCO₃ and Na₂S₂O₃ aq. Solution. The organic layer waswashed with brine, dried over with anhydrous Na₂SO₄, and concentrated todryness to give the crude 101-1 (1.5 g) as a white solid, which was usedfor the next step without further purification.

Preparation of (101-2):

To a mixture of bromo(isobutyl)triphenylphosphorane (4.8 g, 12.03 mmol)in anhydrous THF (8 mL) was added t-BuOK (11.2 mL, 11.2 mmol) at 0° C.under nitrogen. The mixture was stirred at R.T. for 1 h. A solution of101-1 (1.0 g, 1.6 mmol) in anhydrous THF (4 mL) was added dropwise at 0°C. The mixture was stirred at R.T. for 3 h. The reaction was quenchedwith a NH₄Cl aq. solution and extracted with DCM. The organic layer wasdried and concentrated to give a residue, which was purified by silicagel column chromatography (5% EtOAc in PE) to give 101-2 (793 mg, 74.4%)as a white solid.

Preparation of (101-3):

To a solution of 101-2 (364 mg, 0.547 mmol) in anhydrous CH₃CN (6 mL)were added TPSCl (414 mg, 1.37 mmol), DMAP (167 mg, 1.37 mmol) and NEt₃(138 mg, 1.37 mmol) at R.T. The mixture was stirred at R.T. for 2 h.NH₄OH (6 mL) was added, and the mixture was stirred for another 1 h. Themixture was diluted with DCM and washed with a NaHCO₃ aq. solution. Theorganic layer was separated and concentrated to give a residue, whichwas purified by silica gel column chromatography (2% MeOH in DCM) togive 101-3 (347 mg, 95.0%) as white solid.

Preparation of (101a):

To a solution of 27-3 (347 mg, 0.52 mmol) in MeOH (10 mL) was added NH₄F(1.5 g) at R.T. The reaction mixture was refluxed for 12 h, and thenfiltered. The filtrate was concentrated in vacuo, and the residue waspurified by silica gel column chromatography (10% MeOH in DCM) to give101a (87 mg, 53%) as a white solid. ¹H NMR (CD₃OD, 400 MHz) δ 8.11 (d,J=7.6 Hz, 1H), 6.03 (dd, J=1.2, 17.6 Hz, 1H), 5.88 (d, J=7.2 Hz, 1H),6.03 (dd, J=1.6, 11.6 Hz, 1H), 5.39 (d, J=10.8 Hz, 1H), 4.88 (dd, J=3.2,60.0 Hz, 1H), 4.41 (dd, J=4.8, 24.4 Hz, 1H), 3.70 (d, J=12.4 Hz, 1H),3.57 (d, J=12.0 Hz, 1H), 3.08-3.14 (m, 1H), 0.94-0.98 (m, 6H). ESI-MS:m/z 626.9 [2M+H]⁺.

Example 99 Preparation of Compound (102a)

Preparation of (102-1):

To a solution of 101-2 (1.0 g, 1.5 mmol) in MeOH (20 mL) was added NH₄F(6 g) at R.T., and the mixture was refluxed overnight. After cooling toR.T., the mixture was filtered, and the filtrate was concentrated. Theresidue was purified by silica gel column chromatography (8% MeOH inDCM) to give 102-1 (400 mg, 85%) as a white solid.

Preparation of (102-2):

To a solution of 102-1 (400 mg, 1.27 mmol) in MeOH (10 mL) was addedPd/C (400 mg) at R.T. The mixture was stirred at R.T. under a balloon ofH₂ for 1.5 h. The mixture was filtered, and the filtrate wasconcentrated in vacuo to give 102-2 (400 mg, 99%) as a white solid.

Preparation of (102-3):

To a solution of 102-2 (400 mg, 1.26 mmol) in anhydrous DMF (5 mL) wereadded imidazole (968 mg, 14.2 mmol), and TBSCl (1.5 g, 10.0 mmol) atR.T. The mixture was stirred at 50° C. overnight. The mixture wasdiluted with DCM and washed with a NaHCO₃ aq. solution. The organiclayer was dried and concentrated. The residue was purified by silica gelcolumn chromatography (10% EA in PE) to give 102-3 (676 mg, 98%) as awhite solid.

Preparation of (102-4):

To a solution of 102-3 (676 mg, 1.24 mmol) in anhydrous CH₃CN (6 mL)were added TPSCl (941 mg, 13.11 mmol), DMAP (379 mg, 3.11 mmol) and NEt₃(314 mg, 3.11 mmol) at R.T. The reaction was stirred at R.T. for 3 h.NH₄OH (1 mL) was added, and the reaction was stirred for 4 h. Themixture was diluted with DCM and washed with a NaHCO₃ solution. Theorganic layer was dried and concentrated. The residue was purified bysilica gel column chromatography (2% MeOH in DCM) to give 102-4 (450 mg,67%) as a white solid.

Preparation of (102a):

To a solution of 102-4 (450 mg, 0.83 mmol) in MeOH (10 mL) was addedNH₄F (2 g) at R.T. The reaction mixture was refluxed overnight. Aftercooling to R.T., the mixture was filtered, and the filtrate wasconcentrated. The residue was purified by silica gel columnchromatography (8% MeOH in DCM) to give 102a (166.6 mg, 64%) as a whitesolid. ¹H NMR (CD₃OD, 400 MHz) δ 8.09 (d, J=7.6 Hz, 1H), 6.07 (d, J=3.6Hz, 1H), 6.05 (d, J=2.8 Hz, 1H), 5.89 (d, J=7.6 Hz, 1H), 5.03 (dd,J=5.2, 57.2 Hz, 1H), 4.41 (dd, J=4.2, 17.2 Hz, 1H), 3.74 (d, J=12.0 Hz,1H), 3.54 (d, J=12.0 Hz, 1H), 1.23-1.78 (m, 5H), 0.90 (d, J=6.4 Hz, 6H).ESI-MS: m/z 631.1 [2M+H]⁺.

Example 100 Preparation of Compound (103a)

Preparation of (103-2):

103-1 (3.8 g, 6.9 mmol) in 80% AcOH aq. was stirred at 50° C. for 4 h.The mixture was concentrated to give a residue, which was purified bysilica gel column chromatography (5% MeOH in DCM) to give the uridinederivative (1.5 g, 78.2%) as a white solid. To a solution of the uridinederivative (1.5 g, 5.4 mmol) in Py (10 mL) was added Ac₂O (1.38 g, 13.5mmol) at R.T. The mixture was stirred at R.T. for 12 h. The mixture wasconcentrated to give a residue, which was purified by silica gel columnchromatography (20% EA in PE) to give 103-2 (1.3 g, 68%) as a whitesolid.

Preparation of (103-3):

To a solution ofN-(5-fluoro-2-hydroxy-1,2-dihydropyrimidin-4-yl)benzamide (0.5 g, 2.1mmol) in anhydrous PhCl (5 mL) was added ammonium sulfate (6 mg, 0.043mmol), followed by HMDS (0.7 g, 4.3 mmol). The mixture was heated to130° C. for 8 h. The mixture was concentrated under vacuum to 2 mL, andthen cooled to 0° C. TMSOTf (310 mg, 1.4 mmol) was then added. Afterstiffing for 10 min at 0° C., 103-2 (150 mg, 0.4 mmol) in PhCl (5 mL)was added. The mixture was stirred at 130° C. for 10 h. The mixture wasconcentrated, and the residue was re-dissolved in DCM (10 mL), washedwith water (5 mL) and saturated NaHCO₃. The organic layer was dried overNa₂SO₄, evaporated to dryness and the crude product was purified bysilica gel column chromatography (60% PE in EA) to give 103-3 (30 mg,16%) as a white solid.

Preparation of (103a):

A solution of 103-3 (150 mg, 0.34 mmol) in NH₃/MeOH (10 mL) was stirredat R.T. for 3 h. The mixture was concentrated, and the residue waspurified by HPLC separation (0.1% HCOOH in water and MeCN) to give 103a(60 mg, 60%) as a white solid. ¹H NMR (CD₃OD, 400 MHz) δ 8.28 (d, J=6.8Hz, 1H), 6.10 (dd, J=2.0, 15.2 Hz, 1H), 4.99-5.15 (m, 1H), 4.62-4.65 (m,1H), 4.49-4.55 (m, 2H), 3.89 (dd, J=1.6, 12.0 Hz, 1H), 3.75 (dd, J=1.2,12.0 Hz, 1H). ESI-MS: m/z 613.1 [2M+Na]⁺.

Example 101 Preparation of Compound (104a)

Preparation of (104-1):

103-3 (150 mg, 0.31 mmol) was dissolved in 80% aqueous acetic acid (3mL). The solution was heated to reflux for 2 h. The mixture was cooledto ambient temperature and diluted with water (5 mL), neutralized topH>7 with saturated NaHCO₃ and extracted with EA. The organic layer wasdried and evaporated to dryness. The residue was purified by silica gelcolumn chromatography (50% EA in PE) to give 104-1 (80 mg, 70%) as awhite solid.

Preparation of (104a):

104-1 (80 mg, 0.22 mmol) in saturated NH₃/MeOH (10 mL) was stirred atR.T. for 3 h. The mixture was concentrated, and the residue was purifiedby silica gel column chromatography (5% MeOH in DCM) to give 104a (40mg, 60%) as a white solid. ¹H NMR (CD₃OD, 400 MHz) δ 8.30 (d, J=6.8 Hz,1H), 6.18 (dd, J=4.0, 14.0 Hz, 1H), 5.13-5.65 (m, 1H), 4.52-4.56 (m,1H), 3.980-3.95 (m, 2H), 3.76 (s, 3H). ESI-MS: m/z 319.1 [M+Na]⁺.

Example 102 Preparation of Compound (105a)

Preparation of (105-2):

To a solution of triethylammoniumbis(isopropyloxycarbonyloxymethyl)phosphate (0.065 mmol, prepared from22 mg of bis(POC)phosphate and Et₃N) in THF was added 105-1 (31 mg; 0.05mmol). The resulting mixture evaporated, and the residue was renderedanhydrous by coevaporation with pyridine, followed by toluene. Theanhydrous evaporated residue was dissolved THF (1 mL) and cooled in anice-bath. To the solution was added diisopropylethyl amine (35 μL; 4equiv), followed by BOP-Cl (25 mg; 2 equiv) and 3-nitro-1,2,4-triazole(11 mg; 2 equiv). The mixture was stirred at 0° C. for 90 min. Themixture was diluted with CH₂Cl₂, washed with saturated aq. NaHCO₃ andbrine, and dried with Na₂SO₄. The evaporated residue was purified onsilica (10 g column) with a CH₂Cl₂/i-PrOH solvent system (3-10%gradient) to give 105-2 (13 mg, 28%).

Preparation of (105a):

A solution of 105-2 (13 mg; 0.014 mmol) in 80% aq. HCOOH (2 mL) wasstirred at R. T. for 3 h. The mixture was evaporated and thencoevaporated with toluene. The product was purified on silica (10 gcolumn) with a CH₂Cl₂/MeOH solvent system (4-15% gradient) to give 105a(7 mg, 78%). ¹H-NMR (DMSO-d₆): δ 7.52 (d, 1H), 7.28, 7.24 (2 br s, 2H)5.92 (dd, 1H), 5.74 (d, 1H), 5.69 (d, 1H), 5.62 (d, 4H), 4.97 (ddd, 1H),4.82 (m, 2H), 4.38 (dt, 1H), 4.07 (m, 2H), 1.23 (m, 12H), 1.04 (m, 1H),0.37 (m, 4H). ³¹P-NMR (DMSO-d₆): δ −4.51. ¹⁹F-NMR (DMSO-d₆): δ −199.23(dt). MS: m/z=598.4 (M+1).

Example 103 Preparation of Compound (106a)

Preparation of (106-1):

106-1 (15 mg; 30% yield) was prepared in the same manner from 43-5 (32mg; 0.057 mmol) and bis(POC)phosphate (24 mg) with DIPEA (40 μL), BopCl(29 mg) and 3-nitro-1,2,4-triazole (13 mg) as 105-2 from 105-1.

Preparation of (106a):

106-1 (15 mg) was converted in formic acid to 106a (8 mg; 78% yield) inthe same manner as 105-2 to 105a. ¹H-NMR (DMSO-d₆): δ 7.55 (d, 1H),7.32, 7.27 (2 br s, 2H) 6.06 (dd, 1H), 5.84 (d, 1H), 5.73 (d, 1H), 5.61(d, 4H), 5.08 (ddd, 1H), 4.83 (m, 2H), 4.36 (m, 1H), 4.21 (dd, H), 4.16(dd, 1H), 3.56 (d, 1H), 3.49 (d, 1H), 3.28 (s, 3H), 1.25, 1.24 (2 d,12H). ³¹P-NMR (DMSO-d₆): δ −4.45. MS: m/z=602.4 (M+1).

Example 104 Preparation of Compound (107a)

Preparation of (107-1):

107-1 (30 mg; 30% yield) was prepared in the same manner from 40-10 (65mg; 0.115 mmol) and bis(POC)phosphate (49 mg) with DIPEA (80 μL), BopCl(58 mg) and 3-nitro-1,2,4-triazole (26 mg) as 105-2 from 105-1.

Preparation of (106a):

107-1 (30 mg) was converted in formic acid to 107a (15 mg; 73% yield) inthe same manner as 105-2 to 105a. ¹H-NMR (DMSO-d₆): δ 7.60 (d, 1H),7.36, 7.32 (2 br s, 2H) 6.02 (m, 2H), 5.74 (d, 1H), 5.62 (m, 4H), 5.17(ddd, 1H), 4.99 (dq, 1H), 4.83 (m, 2H), 4.61 (m, 1H), 4.19 (m, 2H), 1.40(dd, 3H), 1.24, 1.23 (2 d, 12H). ³¹P-NMR (DMSO-d₆): δ −4.52. ¹⁹F-NMR(DMSO-d₆): δ −185.92 (m, 1F), −200.48 (d, 1F). MS: m/z=604.3 (M+1).

Example 105 Preparation of Compound (108a)

To a solution of 4′-ethyl-2′-fluorocytidine (50 mg, 0.183 mmol) in DMF(1 mL) were added DCC (113 mg, 0.55 mmol), isobutyric acid (48.54 μl,0.55 mmol) and DMAP (22 mg, 0.183 mmol). The mixture was stirred at R.T.overnight. The mixture was filtered, and the filtrate was concentratedwith a rotary evaporator until half of its original volume was achieved.EA was added to the mixture. The mixture was washed with water, followedby brine. The mixture was dried over anhydrous Na₂SO₄ and concentratedin vacuo to give a residue, which was purified by silica gel withDCM/MeOH=95:5 to give 108a (40.8 mg, 54%) as a white solid. ¹H NMR(DMSO-d6, 400 MHz) δ 7.67 (d, J=7.2 Hz, 1H), 7.34 (br s, 2H), 5.85, 5.8(2d, J=21.2, 22 Hz, 1H), 5.72 (d, J=7.6 Hz, 1H), 5.55-5.41 (m, 2H), 4.1(q, 2H), 2.68-2.52 (m, 2H), 1.77-1.64 (m, 2H), 1.13, 1.14 (2s, 2×3H),1.09-1.07 (m, 6H), 0.96 (t, J=7.6 Hz, 3H); MS m/z 414 (M−H⁺), 829(2M+H⁺).

Example 106 Preparation of Compound (109a)

3′,5′-diacetylnucleoside (36 mg, 1 mmol) was dissolved in methanolsaturated with NH₄OH and kept overnight at R.T. The solvent wasevaporated, and the product isolated by column chromatography ingradient of methanol in DCM from 0 to 15% on a 10 g Biotage cartridge.The product was 109a obtained (20 mg, 73%). ¹H-NMR (DMSO-d₆): δ 11.4 (s,1H), 11.84-11.82 (d, 1H); 6.10-6.05 (m, 1H), 5.95-5.83 (d, 1H), 5.71 (s,1H), 5.65-5.63 (d, 1H), 5.37-3.36 (t, 1H), 5.26-5.20 (t, 1H), 5.11-5.07(t, 1H), 4.56-4.55 (m, 1H), 4.46-4.33 (m, 2H), 3.58-3.56 (m, 2H). MS277.2 (M−H).

Example 107 Preparation of Compound (110a)

Preparation of (110-1):

To a solution of 70a (6.55 g, 2.1 mmol) and the benzoyl protected basemoiety (2.3 g, 5.3 mmol) in PhCl (50 mL) was added TMSOTf (3.6 g, 16.1mmol). After addition, the mixture was heated to 140° C. for 8 h. Themixture was cooled to R.T., and evaporated to give a residue. Theresidue was re-dissolved in DCM and washed with saturated NaHCO₃ andbrine. The organic layer was dried and concentrated to give a residue,which was purified by silica gel column (40% EA in PE) to give 110-1(300 mg, 10%) as a white solid.

Preparation of (110a):

110-1 (300 mg, 0.55 mmol) in 80% aqueous acetic acid (5 mL) was heatedto reflux for 2 h. The mixture was cooled to ambient temperature anddiluted with water (5 mL), and then extracted with EA. The organic layerwas washed with saturated NaHCO₃ and brine. The mixture was dried andconcentrated to give a residue, which was purified by silica gel column(10% EA in PE) to give the protected uridine derivative (180 mg, 70%) asa white solid. The protected uridine derivative (180 mg, 0.4 mmol) insaturated NH₃/MeOH (10 mL) was stirred at R.T. for 3 h. The mixture wasconcentrated to give a residue, which was purified by preparative HPLC(0.1% HCOOH in water and MeCN) to give 110a (80 mg, 60%) as a whitesolid. ¹H NMR (CD₃OD, 400 MHz) 88.31 (d, J=6.8 Hz, 1H), 6.17 (dd, J=4.0,14.0 Hz, 1H), 5.13-5.27 (m, 1H), 4.52-4.56 (m, 1H), 3.92 (dd, J=12.0,58.8 Hz, 2H). ESI-TOF-MS: m/z 334.7 [M+Na]⁺.

Example 108 RSV Antiviral Assays

CPE reduction assays are performed as described by Sidwell and Huffmanet al., Appl Microbiol. (1971) 22(5):797-801 with slight modifications.HEp-2 cells (ATCC) at a concentration of 6000 cell/well are infectedwith RSV Long strain (ATCC) at a multiplicity of infection (m.o.i.) of0.01, and each of the test compounds are provided to duplicate wells atfinal concentrations starting from 100 μM using ⅓ stepwise dilutions.For each compound, two wells are set aside as uninfected, untreated cellcontrols (CC), and two wells per test compound receive virus only as acontrol for virus replication (VC). The assay is stopped after 6 days,before all of the cells in the virus-infected untreated control wellsexhibited signs of virus cytopathology (giant cell formation, syncytia).At the end of the incubation, 20 μl of cell counting kit-8 reagent(CCK-8, Dojindo Molecular Technologies, Inc.) are added to each well.After 4 hour incubation, the absorbance is measured in each wellaccording to manufacturer's instruction, and the 50% effectiveconcentration (EC₅₀) is calculated by using regression analysis, basedon the mean O.D. at each concentration of compound.

RT-PCR based assays were performed in HEp-2 cells (ATCC: CCL-23) at aconcentration of 20000 cell/well were plated in 96 well plates andincubated overnight. Each of the test compounds were 1/3 seriallydiluted and dosed to HEp-2 cells in duplicates. The highest finalconcentration for each compound was 100 uM. After 24 hour compoundpre-incubation, RSV A2 (ATCC: VR-1540) at MOI of 0.1 was added. Twowells per compound were set aside as uninfected, untreated cell controls(CC), and four wells per test compound received virus only as a controlfor virus replication (VC). The assay was stopped 4 days after virusinfection and conditioned media was removed for viral RNA isolation. Thequantities of the RSV virus were measured by real-time PCR using a setof RSV specific primers and probe. The data was analyzed with Prismsoftware with EC50 defined as drug concentration that reduced the viralload 50% from the viral control (VC).

Standard RSV polymerase assays were conducted in the presence of 3 μLextract of RSV-infected cells in a reaction buffer containing 50 mMtris-acetate pH 8, 120 mM K-acetate, 4.5 mM MgCl₂, 5% glycerol, 2 mMEDTA, 50 ug/mL BSA, and 3 mM DTT. Varying concentration of testcompounds were used to initiate RNA synthesis for 120 mins at 30° C.,and radioactive 33P GTP (15 uCi) was used as tracer. The reaction wasstopped by adding 50 mM EDTA, and RNA samples were purified through G-50size exclusion spin columns and phenol-chloroform extraction. Theradio-labeled RNA products were resolved by electrophoresis on a 6%polyacrylamide TBE gel, and visualized and quantitated after beingexposed on a phosphorImager screen. Polymerase inhibition experiments(IC₅₀) were conducted the same way in the presence of increasingconcentration of test compounds.

Compounds of Formula (I), Formula (II) and Formula (III) are active inthe assay as noted in Tables 6 and 7. In Table 6, ‘A’ indicates anEC₅₀<2 μM, ‘B’ indicates an EC₅₀ of ≧2 μM and <10 μM and ‘C’ indicatesan EC₅₀≧10 μM and <50 μM. In Table 7, ‘A’ indicates an EC₅₀<1 μM, ‘B’indicates an EC₅₀ of ≧1 μM and <10 μM and ‘C’ indicates an EC₅₀≧10 μMand <100 μM.

TABLE 6 Activity of compounds as determined by RSV polymerase assay No.EC₅₀ 35a A 36a A 36c A 36e A 36i  B 36j  B 56a B 56a B 56c A  56da A 56eA 97a A 97b A 97c A 97d A 97g A 98b A 98c A

TABLE 7 Activity of compounds as determined by RT-PCR assay No. EC₅₀  1aC  2a C  3a A  4a C  7a A  9a C 11a B 13a C 14a A 20a B 21a A 22a C 23aA 25a C 26a B 27a B 28a B 30a A 31a B 33a A 39a B 41a B 46a B 45a C 48aB 50a A 52a A 58a C 69a A 71a A 73a C 76a A 81a B 82a A 83a B 85a A 86aA 87a A 92a C 105a  C 106a  C 108a  B — — — — — — — — — — — —

Example 109 Influenza Antiviral Assay

Human lung carcinoma A549 cells (ATCC, Manassas, Va.) were plated at adensity of 5×10⁴ cells/mL (5×10³ cells/well) in assay media (Ham's F12media supplemented with 0.3% FBS, 1% penicillin/streptomycin (allMediatech, Manassas, Va.) and 1% DMSO (Sigma-Aldrich, St Louis, Mo.)) inblack 96-well plates. After 24 hours, serially diluted test compoundswere added to cells and incubated for an additional 24 hours. Cells wereinfected with 250 IU/well of Influenza strain A/WSN/33 (H1N1) (Virapur,San Diego Calif.) and incubated for 20 hours at 37° C., 5% CO₂. The cellculture supernatant was aspirated off and 50 μL of 25 μM2′-(4-Methylumbelliferyl)-α-D-N-acetylneuraminic acid (Sigma-Aldrich)dissolved in 33 mM MES, pH 6.5 (Emerald Biosystems, Bainbridge Island,Wash.) was added to the cells. After incubation for 45 mins at 30° C.,reactions were stopped by addition of 150 μL stop solution (100 mMglycine, pH 10.5, 25% ethanol, all Sigma-Aldrich). Fluorescence wasmeasured with excitation and emission filters of 355 and 460 nm,respectively, on a Victor X3 multi-label plate reader (Perkin Elmer,Waltham, Mass.). Cytotoxicity of uninfected parallel cultures wasdetermined by addition of 100 μL of CellTiter-Glo® reagent (Promega,Madison, Wis.), and incubation for 10 mins at R.T. Luminescence wasmeasured on a Victor X3 multi-label plate reader.

Compounds of Formula (I), Formula (II) and Formula (III) are active inthe assay as noted in Table 8, where ‘A’ indicates an EC₅₀<20 μM, ‘B’indicates an EC₅₀ of ≧20 μM and <100 μM and ‘C’ indicates an EC₅₀≧100 μMand <250 μM.

TABLE 8 Activity of compounds No. % Inhibition  1a C  2a C  3a C  4a C 6a C  7a C  9a C 12a C 16a C 17a C 18a C 20a C 21a C 22a C 23a C 25a A26a C 27a B 28a C 30a C 31a C 39a B

Example 110 Influenza Pol Assay

Recombinant influenza polymerase trimer is obtained as described(Aggarwal S. et al., PLoS ONE 2010). Standard RNA polymerization assaysare conducted in the presence of 0.15 uM enzyme, 1.5 uM 50-meroligonucleotide template, 400 uM AG primer and varying concentration ofthe test compounds are incubated together for 40 minutes at 30° C.Radioactive 33P GTP are used as the tracer and the radio-labeled RNAproducts are resolved by electrophoresis on a 15% polyacrylamide TBEgel, and is visualized and quantitated after being exposed on aphosphorImager screen. Polymerase inhibition experiments (IC₅₀) areconducted the same way in the presence of increasing concentration oftest compounds.

Although the foregoing has been described in some detail by way ofillustrations and examples for purposes of clarity and understanding, itwill be understood by those of skill in the art that numerous andvarious modifications can be made without departing from the spirit ofthe present disclosure. Therefore, it should be clearly understood thatthe forms disclosed herein are illustrative only and are not intended tolimit the scope of the present disclosure, but rather to also cover allmodification and alternatives coming with the true scope and spirit ofthe invention.

What is claimed is:
 1. A compound selected from Formula (I), or apharmaceutically acceptable salt thereof:

wherein: B^(1A) is an optionally substituted heterocyclic base or anoptionally substituted heterocyclic base with a protected amino group;R^(1A) is selected from the group consisting of hydrogen, an optionallysubstituted acyl, an optionally substituted O-linked amino acid,

the dashed line (------) is absent; R^(2A) is selected from the groupconsisting of an unsubstituted C₁₋₆ alkyl, a halogen substituted C₁₋₆alkyl, a hydroxy substituted C₁₋₆ alkyl, an alkoxy substituted C₁₋₆alkyl, a sulfenyl substituted C₁₋₆ alkyl, an optionally substituted C₂₋₆alkenyl, an optionally substituted C₂₋₆ alkynyl, an optionallysubstituted C₃₋₆ cycloalkyl, an optionally substituted —O—C₁₋₆ alkyl, anoptionally substituted —O—C₃₋₆ alkenyl, an optionally substituted—O—C₃₋₆ alkynyl and cyano; R^(3A) is selected from the group consistingof OH, —OC(═O)R″^(A) and an optionally substituted O-linked amino acid;R^(4A) is fluoro or chloro; R^(5A) is hydrogen or halogen; R^(6A),R^(7A) and R^(8A) are independently selected from the group consistingof absent, hydrogen, an optionally substituted C₁₋₂₄ alkyl, anoptionally substituted C₂₋₂₄ alkenyl, an optionally substituted C₂₋₂₄alkynyl, an optionally substituted C₃₋₆ cycloalkyl, an optionallysubstituted C₃₋₆ cycloalkenyl, an optionally substituted aryl, anoptionally substituted heteroaryl, an optionally substituted aryl(C₁₋₆alkyl), an optionally substituted *—(CR^(15A)R^(16A))_(p)—O—C₁₋₂₄ alkyl,an optionally substituted *—(CR^(17A)R^(18A))_(q)—O—C₁₋₂₄ alkenyl,

or R^(6A) is

and R^(7A) is absent or hydrogen; or R^(6A) and R^(7A) are takentogether to form a moiety selected from the group consisting of anoptionally substituted

and an optionally substituted

wherein the oxygens connected to R^(6A) and R^(7A), the phosphorus andthe moiety form a six-membered to ten-membered ring system; R^(9A) isindependently selected from the group consisting of an optionallysubstituted C₁₋₂₄ alkyl, an optionally substituted C₂₋₂₄ alkenyl, anoptionally substituted C₂₋₂₄ alkynyl, an optionally substituted C₃₋₆cycloalkyl, an optionally substituted C₃₋₆ cycloalkenyl,NR^(30A)R^(31A), an optionally substituted N-linked amino acid and anoptionally substituted N-linked amino acid ester derivative; R^(10A) andR^(11A) are independently an optionally substituted N-linked amino acidor an optionally substituted N-linked amino acid ester derivative;R^(12A), R^(13A) and R^(14A) are independently absent or hydrogen; eachR^(15A), each R^(16A), each R^(17A) and each R^(18A) are independentlyhydrogen, an optionally substituted C₁₋₂₄ alkyl or alkoxy; R^(19A),R^(20A), R^(22A) and R^(23A) are independently selected from the groupconsisting of hydrogen, an optionally substituted C₁₋₂₄ alkyl and anoptionally substituted aryl; R^(21A) and R^(24A) are independentlyselected from the group consisting of hydrogen, an optionallysubstituted C₁₋₂₄ alkyl, an optionally substituted aryl, an optionallysubstituted —O—C₁₋₂₄ alkyl and an optionally substituted —O-aryl;R^(25A) and R^(29A) are independently selected from the group consistingof hydrogen, an optionally substituted C₁₋₂₄ alkyl and an optionallysubstituted aryl; R^(26A) and R^(27A) are independently —C≡N or anoptionally substituted substituent selected from the group consisting ofC₂₋₈ organylcarbonyl, C₂₋₈ alkoxycarbonyl and C₂₋₈ organylaminocarbonyl;R^(28A) is selected from the group consisting of hydrogen, an optionallysubstituted C₁₋₂₄-alkyl, an optionally substituted C₂₋₂₄ alkenyl, anoptionally substituted C₂₋₂₄ alkynyl, an optionally substituted C₃₋₆cycloalkyl and an optionally substituted C₃₋₆ cycloalkenyl; R^(30A) andR^(31A) are independently selected from the group consisting ofhydrogen, an optionally substituted C₁₋₂₄-alkyl, an optionallysubstituted C₂₋₂₄ alkenyl, an optionally substituted C₂₋₂₄ alkynyl, anoptionally substituted C₃₋₆ cycloalkyl and an optionally substitutedC₃₋₆ cycloalkenyl; R″^(A) is an optionally substituted C₁₋₂₄-alkyl; m is0 or 1; p and q are independently selected from the group consisting of1, 2 and 3; r is 1 or 2; Z^(1A), Z^(2A), Z^(3A) and Z^(4A) areindependently O or S; and provided that when R^(1A) is

wherein R^(8A) is an unsubstituted C₁₋₄ alkyl or phenyl optionallypara-substituted with a halogen or methyl and R^(9A) is methyl ester,ethyl ester, isopropyl ester, n-butyl ester, benzyl ester or phenylester of an amino acid selected from the group consisting of glycine,alanine, valine, leucine, phenylalanine, tryptophan, methionine andproline; R^(3A) is OH; R^(4A) is fluoro; R^(5A) is fluoro or hydrogen;and B^(1A) is an unsubstituted uracil; then R^(2A) cannot be —OCH₃;provided that when R^(1A) is H; R^(3A) is OH; R^(4A) is fluoro; R^(5A)is fluoro; and B^(1A) is an unsubstituted cytosine; then R^(2A) cannotbe allenyl; and provided that when R^(1A) is H; R^(3A) is OH; R^(4A) isfluoro; R^(5A) is fluoro; and B^(1A) is an unsubstituted cytosine; thenR^(2A) cannot be ethynyl.
 2. The compound of claim 1, wherein R^(1A) is

is

; and R^(7A) is absent or hydrogen.
 3. The compound of claim 1, whereinR^(1A) is an optionally substituted acyl.
 4. The compound of claim 1,wherein R^(1A) is H.
 5. The compound of claim 1, wherein R^(1A) is anoptionally substituted O-linked amino acid.
 6. The compound of claim 1,wherein R^(1A) is


7. The compound of claim 6, wherein both R^(6A) and R^(7A) areindependently selected from the group consisting of an optionallysubstituted C₁₋₂₄ alkyl, an optionally substituted C₂₋₂₄ alkenyl, anoptionally substituted C₂₋₂₄ alkynyl, an optionally substituted C₃₋₆cycloalkyl, an optionally substituted C₃₋₆ cycloalkenyl, an optionallysubstituted aryl, an optionally substituted heteroaryl and an optionallysubstituted aryl(C₁₋₆ alkyl).
 8. The compound of claim 6, wherein bothR^(6A) and R^(7A) are independently selected from the group consistingof


9. The compound of claim 6, wherein R^(6A) and R^(7A) are both

*—(CR^(15A)R^(16A))_(p)—O—C₁₋₂₄ alkyl or *—(CR^(17A)R^(18A))_(q)—O—C₂₋₂₄alkenyl; or wherein R^(6A) and R^(7A) can be taken together to form amoiety selected from the group consisting of an optionally substituted

and an optionally substituted

wherein the oxygens connected to R^(6A) and R^(7A), the phosphorus andthe moiety form a six-membered to ten-membered ring system.
 10. Thecompound of claim 6, wherein R^(8A) is selected from the groupconsisting of absent, hydrogen, an optionally substituted C₁₋₂₄ alkyl,an optionally substituted C₂₋₂₄ alkenyl, an optionally substituted C₂₋₂₄alkynyl, an optionally substituted C₃₋₆ cycloalkyl and an optionallysubstituted C₃₋₆ cycloalkenyl; and R^(9A) is independently selected fromthe group consisting of an optionally substituted C₁₋₂₄ alkyl, anoptionally substituted C₂₋₂₄ alkenyl, an optionally substituted C₂₋₂₄alkynyl, an optionally substituted C₃₋₆ cycloalkyl, an optionallysubstituted C₃₋₆ cycloalkenyl and NR^(30A)R^(31A).
 11. The compound ofclaim 6, wherein R^(8A) is an optionally substituted aryl; and R^(9A) isan optionally substituted N-linked amino acid or an optionallysubstituted N-linked amino acid ester derivative.
 12. The compound ofclaim 6, wherein R^(1A) is

and, R^(10A) and R^(11A) are both independently an optionallysubstituted N-linked amino acid or an optionally substituted N-linkedamino acid ester derivative.
 13. The compound of claim 1, wherein B^(1A)is selected from the group consisting of:

wherein: R^(A2) is selected from the group consisting of hydrogen,halogen and NHR^(J2), wherein R^(J2) is selected from the groupconsisting of hydrogen, —C(═O)R^(K2) and —C(═O)OR^(L2); R^(B2) ishalogen or NHR^(W2), wherein R^(W2) is selected from the groupconsisting of hydrogen, an optionally substituted C₁₋₆ alkyl, anoptionally substituted C₂₋₆ alkenyl, an optionally substituted C₃₋₈cycloalkyl, —C(═O)R^(M2) and —C(═O)OR^(N2); R^(C2) is hydrogen orNHR^(O2), wherein R^(O2) is selected from the group consisting ofhydrogen, —C(═O)R^(P2) and —C(═O)OR^(Q2); R^(D2) is selected from thegroup consisting of hydrogen, halogen, an optionally substituted C₁₋₆alkyl, an optionally substituted C₂₋₆ alkenyl and an optionallysubstituted C₂₋₆ alkynyl; R^(E2) is selected from the group consistingof hydrogen, hydroxy, an optionally substituted C₁₋₆ alkyl, anoptionally substituted C₃₋₈ cycloalkyl, —C(═O)R^(R2) and —C(═O)OR^(S2);R^(F2) is selected from the group consisting of hydrogen, halogen, anoptionally substituted C₁₋₆alkyl, an optionally substituted C₂₋₆ alkenyland an optionally substituted C₂₋₆ alkynyl; Y² and Y³ are independentlyN or CR¹², wherein R¹² is selected from the group consisting ofhydrogen, halogen, an optionally substituted C₁₋₆-alkyl, an optionallysubstituted C₂₋₆-alkenyl and an optionally substituted C₁₋₆-alkynyl;R^(G2) is an optionally substituted C₁₋₆ alkyl; R^(H2) is hydrogen orNHR^(T2), wherein R^(T2) is independently selected from the groupconsisting of hydrogen, —C(═O)R^(U2) and —C(═O)OR^(V2); and R^(K2),R^(L2), R^(M2), R^(N2), R^(P2), R^(Q2), R^(R2), R^(S2), R^(U2) andR^(V2) are independently selected from the group consisting of C₁₋₆alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₆ cycloalkyl, C₃₋₆ cycloalkenyl,C₆₋₁₀ aryl, heteroaryl, heteroalicyclyl, aryl(C₁₋₆ alkyl),heteroaryl(C₁₋₆ alkyl) and heteroalicyclyl(C₁₋₆ alkyl).
 14. The compoundof claim 1, wherein R^(2A) is a halogen substituted C₁₋₆ alkyl or asulfenyl substituted C₁₋₆ alkyl, and R^(3A) is OH or —OC(═O)R″^(A). 15.The compound of claim 1, wherein the compound of Formula (I) is selectedfrom the group consisting of:

or a pharmaceutically acceptable salt thereof.
 16. The compound of claim1, wherein the compound of Formula (I) is selected from the groupconsisting of:

or a pharmaceutically acceptable salt of the foregoing.
 17. The compoundof claim 1, wherein the compound of Formula (I) is selected from thegroup consisting of:

or a pharmaceutically acceptable salt of the foregoing.
 18. The compoundof claim 1, wherein the compound of Formula (I) is selected from thegroup consisting of:

or a pharmaceutically acceptance salt of the foregoing.
 19. Apharmaceutical composition comprising an effective amount of a compoundof claim 1, or a pharmaceutically acceptable salt thereof, and apharmaceutically acceptable carrier, diluent, excipient, or combinationthereof.
 20. A method for ameliorating or treating a viral infectioncomprising contacting a cell infected with the virus in a subjectidentified as suffering from the viral infection with an effectiveamount of a compound of claim 1, or a pharmaceutically acceptable saltthereof; and wherein the viral infection is selected from aparamyxovirus viral infection and an orthomyxovirus viral infection. 21.A method for ameliorating or treating a viral infection in combinationwith one or more agents comprising administering to or contacting a cellin a subject identified as suffering from the viral infection with aneffective amount of a compound of claim 1, or a pharmaceuticallyacceptable salt thereof; and wherein the viral infection is selectedfrom a paramyxovirus viral infection and an orthomyxovirus viralinfection.
 22. The compound of claim 1, wherein the compound of Formula(I) is

or a pharmaceutically acceptable salt thereof.
 23. The compound of claim1, wherein the compound of Formula (I) is

or a pharmaceutically acceptable salt thereof.
 24. The compound of claim1, wherein the compound of Formula (I) is

or a pharmaceutically acceptable salt thereof.
 25. The compound of claim1, wherein the compound of Formula (I) is

or a pharmaceutically acceptable salt thereof.
 26. The compound of claim1, wherein the compound of Formula (I) is

or a pharmaceutically acceptable salt thereof.
 27. The compound of claim1, wherein the compound of Formula (I) is

or a pharmaceutically acceptable salt thereof.
 28. The compound of claim1, wherein the compound of Formula (I) is

or a pharmaceutically acceptable salt thereof.
 29. The compound of claim1, wherein the compound of Formula (I) is

or a pharmaceutically acceptable salt thereof.
 30. The compound of claim1, wherein the compound of Formula (I) is

or a pharmaceutically acceptable salt thereof.
 31. The compound of claim1, wherein the compound of Formula (I) is

or a pharmaceutically acceptable salt thereof.
 32. The compound of claim1, wherein the compound of Formula (I) is

or a pharmaceutically acceptable salt thereof.
 33. The compound of claim1, wherein the compound of Formula (I) is

or a pharmaceutically acceptable salt thereof.
 34. The compound of claim1, wherein the compound of Formula (I) is

or a pharmaceutically acceptable salt thereof.
 35. The compound of claim1, wherein the compound of Formula (I) is

or a pharmaceutically acceptable salt thereof.
 36. The compound of claim1, wherein the compound of Formula (I) is

or a pharmaceutically acceptable salt thereof.
 37. The method of claim20, wherein the viral infection is a paramyxovirus viral infection. 38.The method of claim 37, wherein the paramyxovirus viral infection ishuman respiratory syncytial virus infection.
 39. The method of claim 21,wherein the viral infection is a paramyxovirus viral infection.
 40. Themethod of claim 39, wherein the paramyxovirus viral infection is humanrespiratory syncytial virus infection.